This protocol has been previously described by Belichenko et al

This protocol has been previously described by Belichenko et al. (2009) and was modified from a Deacon and Rawlins protocol (Deacon and Rawlins 2006; Belichenko et al. 2009). The Y-maze was made of solid white plastic and consisted of two symmetrical arms and one longer arm at 120° angles (longer arm, 20.7 cm length × 12.7 cm height × 7.62 cm width; equal arms, 15.24 cm length × 12.7 cm height × 7.62 cm width). At the Y-27632 structure beginning of trials, mice were placed in the

center of the maze and allowed to freely explore the three arms for 5 min. Inhibitors,research,lifescience,medical Arm entry was defined as having all four limbs inside an arm. The maze was cleaned with 10% ethanol between animals and before the first animal to eliminate traces of odor. The number of arm entries and the number of triads were recorded in order to calculate Inhibitors,research,lifescience,medical the alternation http://www.selleckchem.com/products/brefeldin-a.html percentage, which was calculated by dividing the number of triads by the number

of possible alternations multiplied by 100. A triad was defined as a set of consecutive arm entries (Drew et al. 1973; Hughes 2004). For both T-maze and Y-maze spontaneous alternation test, n = 12 for Inhibitors,research,lifescience,medical both control and Thy1-hAPPLond/Swe+ mice. Morris water maze The MWM was originally designed to test spatial reference memory in rats by observing and recording escape latency, distance moved, and velocity during the search of a hidden escape platform in a large pool (Morris 1984). For our test, we used a large water tank (178 cm in diameter) Inhibitors,research,lifescience,medical filled with water at a temperature of 22.0 ± 1.5°C with a circular platform (17 cm in diameter) placed about 1 cm below the water surface and approximately 50 cm away from the wall. Nontoxic tempera paints (Elmers, Westerville, OH) were used to make the water opaque. The water tank Inhibitors,research,lifescience,medical was completely surrounded by privacy

blinds with at least four visual cues attached to the blinds. Four different shapes including a star shape, circle, rectangle, and diamond each with approximately 6 square feet in surface area were used as visual cues. The visual cues were located approximately 150 cm from the center of the tank. The water tank arena was monitored by an overhead video system that allowed Ethovision to Cilengitide track the mice. During hidden platform training, a platform was positioned in one quadrant of the tank. Mice were released from pseudorandomized drop locations and given 90 sec to find the platform. The distance to the platform was generally the same within a day. The trial either ended when the mice rested on the platform for 10 sec or until the trial duration expired. If mice failed to find the submerged hidden platform during that time, they were guided to it. Mice underwent four trials of training each day (30-min ITIs) for four consecutive days. Upon completion of the hidden platform training, the platform was removed and a 30-sec probe trial was conducted.

4%]; rural, 2/105 [1 9%]; OR, 4 13; 95% CI, 1 09–34 91) [12] Thi

4%]; rural, 2/105 [1.9%]; OR, 4.13; 95% CI, 1.09–34.91) [12]. This disparity is often thought to be solely as a result of longer travel distances and time between collapse and defibrillation, but it is likely to be multifactorial. Often there are fewer prehospital clinicians attending a rural cardiac arrest, compared to urban cardiac arrests, which limit the number of interventions which can be performed

concurrently whilst maintaining consistent, high quality chest compressions. The use of A-CPR has several potential advantages in a rural setting. Chest compressions are able to be provided effectively in the back of a moving vehicle en route to hospital. Without such a device, Inhibitors,research,lifescience,medical paramedics are unrestrained and are at risk of injury in a moving vehicle. Furthermore, mechanical Inhibitors,research,lifescience,medical devices do not tire, and maintain consistent depth and rate of compressions. The main disadvantage of A-CPR is the substantial weight of the device (11.6kg including battery). Limitations This study was potentially

limited by the low number of patients enrolled in the A-CPR arm during the study period. Inhibitors,research,lifescience,medical Also, treatment was not randomised in this study, however we attempted to minimize bias using a matched case–control design and by the use of propensity scores to adjust for known and unknown confounding factors. Finally, survival rates are lower in rural areas when compared to urban Inhibitors,research,lifescience,medical centres [12], making it difficult to recruit sufficient numbers to detect a difference in outcome and therefore evaluate the true utility of A-CPR in the rural and regional prehospital setting. Conclusions A-CPR may improve rate of survival to hospital over traditional C-CPR in selected settings and warrant further studies of this device, particularly examining the potential utility in rural settings. Competing interests Zoll

Medical Australia Pty Ltd provided an unrestricted grant. The funding source had no role in the study design, data collection, data analysis, Inhibitors,research,lifescience,medical data interpretation, writing of the report or the decision to submit for publication. Authors’ contributions PAJ and TS analysed the data for the present paper. PJ wrote the initial draft of the manuscript. All authors contributed to study design, interpretation of the data, intellectual discussion and revision of the manuscript. All authors have Cilengitide made substantive contributions to the study, and all authors endorse the data and conclusions. All authors read and since approved the final manuscript. Pre-publication history The pre-publication history for this paper can be accessed here: http://www.biomedcentral.com/1471-227X/12/8/prepub Acknowledgements We express our sincere thanks to the Paramedics of Ambulance Victoria who participated in this study, and Zoll Medical Australia Pty Ltd for the provision of an unrestricted grant.
Injuries are the cause of 5.8 million deaths annually which accounts for almost 10% of global mortality [1].

41,42 The potential contribution of excitatory synapse pruning du

41,42 The potential contribution of excitatory synapse pruning during adolescence to disease-related changes in DLPFC function depends, in part, on the functional properties of the synapses that are pruned. During early brain development, pruned synapses are functionally immature. Immature glutamate synapses are relatively weak and their maturation involves an activity-dependent increase in strength. Such activity-dependent strengthening might underlie synapse stabilization,

and thus mark for elimination the immature synapses that are not strengthened.43,44 However, recent findings in the developing monkey DLPFC indicate that the excitatory-inputs to layer 3 pyramidal Inhibitors,research,lifescience,medical neurons mature functionally Inhibitors,research,lifescience,medical during the age range when they are present in high density and before synaptic pruning begins.45 Thus, these data suggest that the substantial remodeling

of excitatory connectivity of the primate DLPFC during adolescence primarily involves the elimination of mature synapses, and that some other factor, such as the neuronal source of input, somehow tags mature synapses for pruning.46 Thus, the Inhibitors,research,lifescience,medical presence of functionally mature synapses prior to adolescence supports the hypothesis that the excess in excitatory synapse number prior to adolescence might be able to compensate for a molecular based dysfunction of these synapses in individuals with schizophrenia, and thereby forestall the appearance of the clinical features of the illness until synapse number falls below some

critical threshold.40 Neuroplasticity of inhibitory cortical connections in schizophrenia Prefrontal inhibitory neurotransmission is altered in schizophrenia Studies from multiple Inhibitors,research,lifescience,medical laboratories have consistently found lower levels of the mRNA for the 67 kilodalton isoform of glutamic acid decarboxylase (GAD67), the principal synthesizing enzyme for y-aminobutyric acid (GABA), in Inhibitors,research,lifescience,medical the DLPFC of subjects with schizophrenia.16,22-47,52 At the cellular level, the expression of GAD67 mRNA was not detectable in -25% to 35% of GABA neurons in layers 15 of the DLPFC, but the remaining GABA neurons exhibited normal levels of GAD67 mRNA.16-47 Similarly, expression of the mRNA for the GABA membrane transporter (GAT1), a protein inhibitor Paclitaxel responsible for reuptake of released GABA into nerve terminals, was decreased in a similar minority of GABA neurons.53 These findings suggest that both the synthesis and Anacetrapib reuptake of GABA are lower in a subset of DLPFC neurons in schizophrenia. Subclasses of cortical GABA neurons can be distinguished on the basis of a number of molecular, electro-physiological, and anatomical properties. For example, the affected GABA neurons in schizophrenia include the subclass that selleck chemical EPZ-5676 contain the calcium-binding protein, parvalbumin (PV), which comprise -25% of GABA neurons in the primate DLPFC.

Of the stages, females that were trained during pro

Of the stages, females that were trained during proestrus (stressed 24 hours earlier in di estrus) were

most impaired by stressor exposure.11 Since this stage is associated with elevated levels of estrogen, the hormone is again implicated in these stress effects on conditioning. Figure 3. Contribution of ovarian hormones to the stress effect on learning in females. A. Females that were ovariectomized (OVX) prior to stressor exposure and training were not impaired by stress and exhibited a similar response to those exposed to a sham surgery. … Recall that females under normal unstressed conditions Inhibitors,research,lifescience,medical learn faster in proestrus than in other stages. How might estrogen contribute to both enhanced learning under unstressed conditions and impaired learning after stress? It may be BTB06584? useful to consider the effect of stress on

learning from a slightly different perspective in which stress does not impair conditioning directly, but rather prevents the enhancement, that normally occurs when estrogen levels Inhibitors,research,lifescience,medical are elevated. Neuroanatomical correlates of stress and sex differences in learning These opposite effects of stress in males and females pose Inhibitors,research,lifescience,medical some interesting questions, one being whether there is a neuronal or anatomical substrate that can account for these opposite responses to stress. .First, we considered a potential role for dendritic spines, tiny protrusions on many dendrites Inhibitors,research,lifescience,medical in the brain, which are a source of excitatory input.39 Because they enable connections and associations to be made between adjacent neurons, it

has been hypothesized that they are involved in the formation of associative memories. Despite the pervasiveness of the hypothesis in the literature, there are minimal data in support of this. In fact, the most. potent modulator of dendritic spines so far established is estrogen. Acute Inhibitors,research,lifescience,medical exposure to estradiol enhances spine density in the selleckchem hippocampus of ovariectomized females; moreover, females in proestrus have a greater spine density than females in other stages.40,41 The effect of estrus on spine density is rapid and dramatic, varying as much as 30% over the 5-day cycle. Recently, we compared the changes in spine density across the estrous cycle in females with that, Anacetrapib of males. As shown previously,42 females in proestrus had a greater density of dendritic spines on apical dendrites in area. CA1 of the hippocampus. As shown in Figure 4, we also observed that females in proestrus have a greater density of spines in the hippocampus than do males.43 As discussed, it has long been assumed that dendritic spines participate in learning processes. So docs this change in spine density across the estrous cycle and between the sexes relate to learning ability? At.

15 To assess this approach GRK2 inhibition was tested in rabbits

15 To assess this approach GRK2 inhibition was tested in rabbits in a study where adenovirus encoding for βARKct was administered into the coronaries at the time of myocardial infarction (MI). Three weeks post-gene transfer, GRK2 inhibition resulted in prevention of left ventricular (LV) adverse remodeling, improvement of cardiac contractility, and preservation of βAR signaling and function.16 Similarly, left ventricular remodeling Inhibitors,research,lifescience,medical was reversed by adeno-associated virus encoding for βARKct

gene therapy in a pig model of heart failure.17 This and other studies make the βARKct a promising candidate for future application in human heart failure (moreover Figure 1). Figure 1 Beyond G-protein-coupled receptor blockade. “FIXING” CALCIUM

HANDLING IN FAILING HEARTS sellectchem Impaired calcium homeostasis is a prominent feature of the remodeling process and heart Inhibitors,research,lifescience,medical failure, and it manifests clinically as contractile dysfunction and development of arrhythmias.18 When compared to normal myocytes, the failing heart myocytes exhibit typical changes in intracellular calcium Inhibitors,research,lifescience,medical handling, including impaired extrusion of cytosolic calcium, reduced calcium loading in the cardiac sarcoplasmic reticulum (SR), and defects in the SR calcium release.19 These changes in calcium handling are thought to contribute to the impairment of cardiac contractile functions (Figure 2).20 Figure 2 Correcting Inhibitors,research,lifescience,medical calcium handling in failing hearts. Relaxation of the myofilaments after contraction is facilitated by two mechanisms of calcium extrusion: the rapid re-sequestration of calcium into the SR and calcium efflux outside of the cells Inhibitors,research,lifescience,medical through the plasma membranes. The sarco-endoplasmic reticulum calcium ATPase 2 pump (SERCA2) is localized on the SR membrane

and is responsible for the re-uptake of calcium from the cytoplasm into the SR lumen. Since the amount of calcium released through the ryanodine receptors (RyR) during each cardiac cycle is proportional to the calcium content of the SR, the SERCA2 activity is a critical determinant of both relaxation (via calcium re-uptake into the SR) and contractility AV-951 (via controlling the amount of calcium in the SR) in the cardiomyocytes.21 Indeed, experimental studies in animal models of heart failure have shown that increasing the expression of SERCA2a in cardiomyocytes normalizes intracellular calcium cycling, restores both relaxation and contractile function, and results in significant improvement in survival.22 Following the success of these animal studies, the Calcium Upregulation by Percutaneous Administration of Gene Therapy in Cardiac Disease (CUPID) trial enrolled 39 patients to receive intracoronary adeno-associated virus type 1 encoding for SERCA2 or placebo.

We have no data to address this issue, which may be a focus of fu

We have no data to address this issue, which may be a focus of future studies. The CCI has some conceptually common items with other measures (feeling as if the situation was unreal, emotional numbness and fear) and some related phenomena (feeling emotionally stuck and sensory impressions). It would be pretentious to address this as convergent validity, but the commonalities are great enough to warrant studying the relationship between the CCI, the IES and the PTSS-10. The correlations with these stress measures Inhibitors,research,lifescience,medical were significant, indicating that the CCI can be used as a predictor for posttraumatic

stress after injuries. It might have been interesting to assess the convergent validity with other measures of peritraumatic responses like the Peritraumatic Distress Inventory (PDI). However, Inhibitors,research,lifescience,medical the main focus of this study was the sensory perception. The assessments at two time points made it possible to study changes in perceived threat during the casualty chain. The level of perceived threat was moderately but significantly higher at the scene of the injury than in the hospital, but there

was a stronger explained variance measured Inhibitors,research,lifescience,medical in hospital. The mean score of dissociation and perceptions were quite similar at both measurement points. Measuring the responses in hospital seems to be sufficient in http://www.selleckchem.com/products/PF-2341066.html identifying those at risk of developing posttraumatic stress. Strengths and Limitations Inhibitors,research,lifescience,medical The CCI showed strong internal consistency and a two-factor scale, despite the fact that the participants were drawn from a physically injured population with a broad range of stress symptoms. Accordingly, the instrument can be used in conscious patients admitted in the ER following a physical incident to see who may be at risk for subsequent posttraumatic stress. It examined a large sample from a region surrounding the capital of Norway. The duration of the threat was assessed by questions about the scene of the injury and

Inhibitors,research,lifescience,medical about the participants’ stay in the hospital. The participants completed the questionnaires some weeks after their accident. The time of assessment (weeks after the accident) raise questions regarding the CCI’s ability to identify patients at risk. Even though a recall bias may be present, those with symptoms after some weeks are most likely at greater risk for symptoms also at a later stage. Analysis showed no significant difference in Cilengitide stress score (IES) between patients BAY 734506 answering close to the accident compared to those answering several weeks after the event. This may confirm that the ability to remember feelings and responses in certain situations should not be underestimated. In the pilot study, patients were assessed within a few days post trauma while admitted to hospital. For most patients the self-assessment was difficult at this time point. Some were sleepy, some stressed and some were cognitively not able to concentrate. This was a major reason for postal assessment after discharge.

Specific measures are taken to ensure compliance of the clinicia

Specific measures are taken to ensure compliance of the clinician with the protocol and adherence of the patient with the procedures and treatments. Formally, efficacy studies define optimal treatment outcomes for narrowly selected patients treated under rigidly controlled and ideal conditions. With a primary focus on symptoms, the assessment of efficacy is based upon the degree to which the level of symptomatology is reduced or eliminated.6,7

Inhibitors,research,lifescience,medical In an efficacy trial, treatment is provided by specially selected and trained clinicians who provide optimal treatment and expend substantial resources to ensure compliance and minimize drop out. Research supported for commercial purposes, particularly that supported by the drug companies themselves, has, of necessity, conformed to the regulatory model. This is the case regardless of whether the site of the study is an academic health center or a community- treatment facility, and regardless of whether the coordination of the study Inhibitors,research,lifescience,medical is done directly by the sponsor or by an intermediary (contract research organization,

or CRO). It is worth noting that those doing clinical Inhibitors,research,lifescience,medical psychotherapeutic or behavioral research have not (yet) adopted this CRO type of Cabozantinib cancer arrangement. The regulator)- model has also been carried over into research that has no industrial sponsorship, even to research on mental disorders that has been directed to government Inhibitors,research,lifescience,medical agencies or foundations. In a treatment study driven by a regulatory model of investigation, there is no minimum effect size or minimum pro portion of rcsponders necessary. In addition,

there is no requirement that the subject population be representative of the kind of patient seen in actual practice. As such, a trial done in accordance with the regulatory model represents only the beginning of a process of clinical development. Inhibitors,research,lifescience,medical Efficacy studies define optimal treatment outcomes for narrowly selected patients treated under rigidly controlled and ideal conditions. The Anacetrapib classic efficacy trial is used to define the gold standard of the best outcome under ideal circumstances. Because of the tight standard of control required in efficacy studies, the policy and practice relevance of these http://www.selleckchem.com/products/Axitinib.html trials will always be limited.8 The clinical trials of cognitive enhancers provide a useful example of the differences between regulatory and public health research. The trials of cognitive enhancers seek to show slowing or reversal of the progression of Alzheimer’s disease or to demonstrate improved management of the symptoms of the disease. These trials typically attempt to show that the course of a progressive disease has been modified. The design of such trials involves great complexities even under optimal conditions.

Many countries do not require that health warnings be placed at t

Many countries do not require that health warnings be placed at the top of the principal display area. In addition, many country laws do not require health warnings to be located where they would not be obstructed by required markings on packs, or damaged/concealed with the opening and closing of packs. Most countries in INK 128 solubility the selection

(except Mexico, Spain, Turkey, Nepal and Australia) do not meet all the requirements for location of health warning labels as required by the FCTC. Though large warnings have been shown to be effective by both smokers and non-smokers [18,19], placing them at the top of the PDA can further enhance their effectiveness and noticeability. Most country laws in the selection did not prohibit

the use of all forms of misleading descriptors on packs, except Australia and Mexico, which comply with all the requirements of the FCTC with respect to this category. Countries’ laws were especially weak in prohibiting the display of quantitative emission yields on their packs. Users of these products may still ascribe lower risks to brands that have lower levels of tar, carbon monoxide or nicotine, attenuating the effect that the prohibition of the use of misleading terms such as “mild” “light”, may have had. Six countries in the selection (South Africa, Kenya, Poland, Indonesia, Philippines and China) are yet to mandate the use of health warnings that contain pictograms. It is also important to note that most of these are low-and middle-income countries, where health literacy may be relatively low.

Though the use of pictograms is not a requirement, countries can strengthen the impact of their warning labels by using graphic color images. Strong warnings that utilize graphic pictograms, and not just text, are shown to be more effective in getting the attention of users, conveying the significance of the text warning and ultimately inducing a change in the perception of risk by the users [18,20-27]. Studies have shown that smokers tend to notice health warnings with pictures more than they do warnings without [21,28]. Pictograms would convey a stronger message, especially in low-literacy settings, or in cases where text warnings are very weak in conveying the harms of tobacco use. Strong health warning messages can influence the decision to initiate or quit smoking GSK-3 [5,6], and these measures can be implemented at no cost to governments [7]. Some countries like Canada [19,29,30], Australia [11], Brazil [31], Singapore [32] and Thailand [33] have seen significant change in perceptions and attitudes toward smoking following implementation of some of these FCTC-recommended best-practices in health warning display. Barriers to implementing best practices in tobacco packaging and labeling, as stipulated by the FCTC, would vary by country. Countries should share their successes and challenges, and collaborate on possible strategies to strengthen their tobacco laws.

(a) Panoramic view (b) Isolated magnified particle Reprinted fr

(a) Panoramic view. (b) Isolated magnified particle. Reprinted from Oliveira et al. [6], with the permission of Editorial Executive, Research … Polymeric micelles are generally lower in size than nanoparticles and liposomes and larger than dendrimers, while sufficiently small (less than 100nm in diameter) to penetrate tissues. Additionally, liposomes can be eventually dissembled after all drug has been delivered [63]. Inhibitors,research,lifescience,medical A small number of reports have been published

on the delivery of NO using polymeric systems. Oliveira et al. [6] developed and characterized PLGA nanoparticles containing the NO donor agent (trans-[RuCl([15]ane)(NO)]2+). One year later, Jain et al. [71] demonstrated that then stabilization of NO pro-drugs and anticancer lead compounds via their incorporation into polymer-protected nanoparticles composed of polystyrene-b-PEG (PS-b-PEG) and PLA-b-PEG may enhance their therapeutic effects. Meanwhile, Yoo et al. [72] described PLGA microparticles containing an NO donor that efficiently delivered NO to the vaginal mucosa, Inhibitors,research,lifescience,medical resulting in improved vaginal blood perfusion, which may have implications in the treatment of female sexual dysfunction. Another potential clinical application of polymeric nanocarriers is in sellectchem topical NO delivery, such as by incorporation of NO donors into a liquid PEG/water matrix [31]. Finally, Inhibitors,research,lifescience,medical Kanayama

et al. [66] reported that PEGylated polymer micelles may be capable of delivering exogenous NO to tumor cells in a photocontrolled manner, resulting in an

NO-mediated antitumor effect, which indicates the promise of this polymeric system in NO-based tumor therapy. 2.2. Dendrimers and Hydrogels Dendrimers are monodisperse macromolecules with a tridimensional Inhibitors,research,lifescience,medical structure that is highly ramificated and regular Inhibitors,research,lifescience,medical around the nucleus [64, 73]. The ability to store NO on a dendritic scaffold using the NO donor N-diazeniumdiolate was first demonstrated by Stasko and Schoenfisch [74]. Benini et al. [75] then reported that the system formed by anchoring of K[RuIII(edta)(Cl)] to poly(amidoamine) dendrimers (PAMAM) can relax aortic rings lacking endothelium and exert trypanocidal effects. Meanwhile, Stasko et al. [76] synthesized two generation-4 PAMAM dendrimers with S-nitrosothiol exteriors (Figure 2) and characterized their Drug_discovery ability to inhibit thrombin-mediated platelet aggregation. Figure 2 Generation-4 PAMAM with a completely modified exterior (64 thiols) of S-nitroso-N-acetyl-D,L-penicillamine (G4-SNAP) or S-nitroso-N-acetylcysteine (G4-NACysNO). Reprinted from Stasko et al. [76], with the permission of American Chemical Society, ACS Publications. … Another interesting delivery system is hydrogel (Figure 3), a three-dimensional hydrophilic polymeric network that can absorb and retain a considerable amount of water while maintaining shape. This system has enormous potential in the design of closed-loop drug delivery.

Although post-processing is relative complex, which may affect th

Although post-processing is relative complex, which may affect the purity of products, these unconventional methods are surely efficient and powerful. Therefore, in the review we will introduce some other unconventional multistep methods which can synthesize shape-controlled and novel silver nanostructures including the double reductants method, etching technique and construction of core-shell nanostructures. Jones et al. [30] covered a number of templates for the preparation of plasmonic nanostructures including solution-phase templates, porous templates and surface mask templates. They have mentioned part of the etching technique and core-shell nanostructures in their review. However, we reviewed these unconventional methods from three perspectives following different rules. The double reductant method is based on different favorable facets of silver nanocrystals produced in different reductants. The etching technique involves the use of an etchant to selectively remove nanoparticles so that nanostructures can be obtained with shape control. The mechanism of construction of core-shell nanostructures is epitaxial selleck chemical growth from core seeds. The optical properties of these nanostructures can be finely tuned corresponding to the shape and size control leading to wide range of potential applications.2.?Double Reductant MethodIt is known that different reductants can offer different reducibility, which plays an important role in shape control of nanostructures. Moreover, favorable facets of nanocrystals are determined by the reductants used. Some reductants prefer to promote growth of (100) facets, while others prefer to (111) or (110) facets. Therefore, complex nanostructures or nanostructures which are not easy to be prepared using one-step methods can be obtained by choosing different reductants in each step leading to desired nanostructures.2.1. N,N-dimethylformamide (DMF) and EGDMF is a well-known organic solvent as well as an active reductant under suitable condition which has been demonstrated [31]. Liz-Marz��n’s group first employed DMF to reduce AgNO3 for the preparation of silver nanostructures which paved a new way for shape control [32]. In their later works, they successfully synthesized nanospheres [33], nanoprisms [34,35] and nanowires [36] via reduction of AgNO3 by DMF in the presence of PVP. In addition, Gao et al. [37] prepared silver decahedrons in high yield with PVP as stabilizer in DMF. Tsuji et al. [38] provided new information on the growth of decahedrons and icosahedrons in DMF through a stepwise route. Lu et al. [39] realized the finely tuned size of nanoplates from 20 to 50 nm by varying the molar ratio of PVP/DMF.