An effective'salt in dimethyl sulfoxide/water'electrolyte enables high-voltage supercapacitor operated at-50℃

Compared with organic electrolytes,aqueous electrolytes exhibit significantly higher ionic conductivity and possess inherent safety features,showcasing unique advantages in supercapacitors.However,challenges remain for low-salt aqueous electrolytes operating at high voltage and low temperature.Herein,we report a low-salt(0.87 m,m means mol kg^(-1))'salt in dimethyl sulfoxide/water'hybrid electrolyte with non-flammability via hybridizing aqueous electrolyte with an organic co-solvent of dimethyl sulfoxide(hydrogen bond acceptor).As a result,the 0.87 m hybrid electrolyte exhibits enhanced electrochemical stability,a freezing temperature below-50℃,and an outstanding ionic conductivity of 0.52mS cm~(-1)at-50℃.Dimethyl sulfoxide can anchor water molecules through intermolecular hydrogen bond interaction,effectively reinforcing the stability of water in the hybrid electrolyte.Furthermore,the interaction between dimethyl sulfoxide and water molecules diminishes the involvement of water in the generation of ordered ice crystals,finally facilitating the low-temperature performance of the hybrid electrolyte.When paired with the 0.87 m'salt in dimethyl sulfoxide/water'hybrid electrolyte,the symmetric supercapacitor presents a 2.0 V high operating voltage at 25℃,and can operate stably at-50℃.Importantly,the suppressed electrochemical reaction of water at-50℃further leads to the symmetric supercapacitor operated at a higher voltage of 2.6 V.This modification strategy opens an effective avenue to develop low-salt electrolytes for high-voltage and low-temperature aqueous supercapacitors.

Excess properties and spectroscopic studies for binary system polyethylene glycol 600 + dimethyl sulfoxide at T =(298.15, 303.15,308.15, 313.15, and 318.15) K

The work presents density(ρ) and viscosity(η) data of binary system polyethylene glycol 600(PEG) + dimethyl sulfoxide(DMSO) over the entire concentration range at T =(298.15, 303.15, 308.15, 313.15 and 318.15) K and atmospheric pressure. On the basis of density and viscosity values, the excess properties of PEG(1) + DMSO(2) mixtures, including excess molar volume(V_m^E), viscosity deviation(Δη), excess free energies of activation(ΔG^(*E)), and isobaric thermal expansion coefficient(αp), were calculated. At the same time, in order to conjecture the density viscosity under different conditions, the density and viscosity data were fitted with the corresponding formula. The calculated results of V_m^E, Δη, and ΔG^(*E) were fitted with the Redlich–Kister equation to derive coefficients and estimate the standard deviations(σ) between the experimental and calculated values. Moreover, the intermolecular interaction of PEG with DMSO was discussed on the basis of FTIR and UV–Vis spectral results of PEG(1) + DMSO(2) mixtures. The results indicated that there were the hydrogen bonding and interactions of hydroxyl hydrogen atoms in PEG with oxygen atoms in DMSO.

Synthesis and Crystal Structure of [(Praseodymium)_2(3,5-Binitro Benzoyloxy)_6 (Dimethyl Sulfoxide)_4] Complex

A novel one-dimensional chain complex [Pr2(bnbo)6(DMSO)4] (bnbo=3,5-binitro benzoyloxy, DMSO= dimethyl sulfoxide) with bridging carboxyl groups was synthesized and its structure has been determined by single-crystal X-ray methods. In the complex, a pair of adjacent metal ions are alternately connected by four or two carboxylate groups to form an infinite chain of 8-coordinated Pr3+ ions. The complex (Pr2C50H42N12O40S4 ) crystal system is triclinic, with space group P1, a=14.2890(3), b=14.3427(3), c=20.1601(2)? =76.636(1), b=84.496(1), =60.316(1)? V=3491.4(1)?, Z=2, Mr =1861.02, Dc=1.770 g/cm3, m=1.608mm-1, F(000)=1856, the final R=0.0776 and wR=0.1724 for 8804 reflections with I > 2s(I).

Innovate combination of sevoflurane dilution in dimethyl sulfoxide: A stability study by gas chromatography and nuclear magnetic resonance

To investigate physicochemical stability of sevofuranein dimethyl sulfoxide using gas chromatography with a fame ionization detector and nuclear magnetic reso-nance （NMR）.METHODSUndiluted sevoflurane, plus dilutions 1：2, 1：5, 1：10, 1：25, and 1：50 in dimethyl sulfoxide were prepared in a vertical laminar fow cabinet class Ⅱ type B and stored at different temperatures （23 ℃, 6 ℃, and -10 ℃） for 45 d. Sterile 1 mL polypropylene amber syringes to minimize light degradation, caps and needles were used. The presence of sevofurane and its degradation products in the samples was determined by gas chroma-tography with flame ionization detector （260 ℃, 40min）, and by 1H, 19F, and proton-decoupled 19F nuclearmagnetic resonance.RESULTS The gas chromatography analysis showed sevofluraneand dimethyl sulfoxide （DMSO） retention times were 2.7and 13.0 min, respectively. Pure DMSO injection into thecolumn resulted in two additional peaks at 2.1 and 2.8min. The same sevofurane peak at 2.7 min was observedin all the dilutions at -10 ℃, 4 ℃ and 25 ℃. The NMRspectra showed signals consistent with the sevoflurane structure in all the dilutions at -10 ℃, 4 ℃ and 25 ℃. In the 1H spectrum, two signals corresponding to the sevoflurane molecule were observed at 5.12 and 4.16 parts per million （ppm5）. In the 19F-NMR spectrum, two signals were observed at -76.77 ppm and -157.13 ppm. In the 19F NMR CPD, two signals were observed at -76.77 ppm and -157.13 ppm. The first one showed a doublet （JF-F = 3.1 Hz） which integrated by six fluorine nuclei from the hexafluoro-isopropyl group. The second signal was integrated by a fuorine atom and showed a septuplet （JF-F = 3.1 Hz）.CONCLUSIONThis study shows that different concentrations ofsevofurane in dimethyl sulfoxide retain their chemicalcomposition after exposure to different temperaturesfor a period of 45 d.

LYOTROPIC AND THERMOTROPIC LIQUID CRYSTALL INE TRIALKYL CELLULOSES OBTAINED DIRECTLY FROM CELLULOSE ACETATE IN DIMETHYL SULFOXIDE

Highly substituted n-atkyl celluloses with sidechains 3 to 10 carbon atoms long have been prepared from cellulose acetate, sodium hydroxide and n-alkyl bromides with dimethyl sulfoxide as solvent. Synthetic conditions of n-alkyl celluloses were studied with respect to reaction temperature, time and yield. The molecular structure of the n-alkyl celluloses, which were obtained as white powders or as sticky, soft and birefringent solids at room temperature, was investigated by IR and NMR spectra and elemental analysis. The highly substituted n-alkyl celluloses all exhibited both therotropic and lyotropic liquid crystalline cholesteric phases in some non-polar solvents. The metting behavior and solubility of the n-alkyl celluloses were examined.

Inhibition of matrix metalloproteinase-9 secretion by dimethyl sulfoxide and cyclic adenosine monophosphate in human monocytes

BACKGROUND Matrix metalloproteinases(MMPs),including MMP-9,are an integral part of the immune response and are upregulated in response to a variety of stimuli.New details continue to emerge concerning the mechanistic and regulatory pathways that mediate MMP-9 secretion.There is significant evidence for regulation of inflammation by dimethyl sulfoxide(DMSO)and 3',5'-cyclic adenosine monophosphate(cAMP),thus investigation of how these two molecules may regulate both MMP-9 and tumor necrosis factorα(TNFα)secretion by human monocytes was of high interest.The hypothesis tested in this study was that DMSO and cAMP regulate MMP-9 and TNFαsecretion by distinct mechanisms.AIM To investigate the regulation of lipopolysaccharide(LPS)-stimulated MMP-9 and tumor necrosis factorαsecretion in THP-1 human monocytes by dimethyl sulfoxide and cAMP.METHODS The paper describes a basic research study using THP-1 human monocyte cells.All experiments were conducted at the University of Missouri-St.Louis in the Department of Chemistry and Biochemistry.Human monocyte cells were grown,cultured,and prepared for experiments in the University of Missouri-St.Louis Cell Culture Facility as per accepted guidelines.Cells were treated with LPS for selected exposure times and the conditioned medium was collected for analysis of MMP-9 and TNFαproduction.Inhibitors including DMSO,cAMP regulators,and anti-TNFαantibody were added to the cells prior to LPS treatment.MMP-9 secretion was analyzed by gel electrophoresis/western blot and quantitated by ImageJ software.TNFαsecretion was analyzed by enzyme-linked immuno sorbent assay.All data is presented as the average and standard error for at least 3 trials.Statistical analysis was done using a two-tailed paired Student t-test.P values less than 0.05 were considered significant and designated as such in the Figures.LPS and cAMP regulators were from Sigma-Aldrich,MMP-9 standard and antibody and TNFαantibodies were from R&D Systems,and amyloid-βpeptide was from rPeptide.RESULTS In our investigation of MMP-9 secretion from THP-1 human monocytes,we made the following findings.Inclusion of DMSO in the cell treatment inhibited LPSinduced MMP-9,but not TNFα,secretion.Inclusion of DMSO in the cell treatment at different concentrations inhibited LPS-induced MMP-9 secretion in a dosedependent fashion.A cell-permeable cAMP analog,dibutyryl cAMP,inhibited both LPS-induced MMP-9 and TNFαsecretion.Pretreatment of the cells with the adenylyl cyclase activator forskolin inhibited LPS-induced MMP-9 and TNFαsecretion.Pretreatment of the cells with the general cAMP phosphodiesterase inhibitor IBMX reduced LPS-induced MMP-9 and TNFαin a dose-dependent fashion.Pre-treatment of monocytes with an anti-TNFαantibody blocked LPSinduced MMP-9 and TNFαsecretion.Amyloid-βpeptide induced MMP-9 secretion,which occurred much later than TNFαsecretion.The latter two findings strongly suggested an upstream role for TNFαin mediating LPS-stimulate MMP-9 secretion.CONCLUSION The cumulative data indicated that MMP-9 secretion was a distinct process from TNFαsecretion and occurred downstream.First,DMSO inhibited MMP-9,but not TNFα,suggesting that the MMP-9 secretion process was selectively altered.Second,cAMP inhibited both MMP-9 and TNFαwith a similar potency,but at different monocyte cell exposure time points.The pattern of cAMP inhibition for these two molecules suggested that MMP-9 secretion lies downstream of TNFαand that TNFαmay a key component of the pathway leading to MMP-9 secretion.This temporal relationship fit a model whereby early TNFαsecretion directly led to later MMP-9 secretion.Lastly,antibody-blocking of TNFαdiminished MMP-9 secretion,suggesting a direct link between TNFαsecretion and MMP-9 secretion.

New insights into the effect of molecular crowding environment induced by dimethyl sulfoxide on the conformation and stability of G-quadruplex

Various structures of G-quadruplex in biosystems play an important role in different diseases and are often regulated by a variety of molecular crowding environments induced by internal and even external factors(e.g.,a solvent).Dimethyl sulfoxide(DMSO),a universal solvent,has been widely used in biological studies and for drug therapy,but little is known regarding its effect on G-quadruplex structure and stability.Here,we report the influence of molecular crowding environment induced by DMSO on the conformation and stability of G-quadruplex structure.We show that the G-quadruplex-forming sequences such as human telomeric sequence,which may have diverse conformations in different environments,tend to convert their topologies to parallel structures under the molecular crowding stimulated by DMSO.Moreover,DMSO can increase the stability of the parallel and antiparallel topologies,especially the parallel G-quadruplex sequence c-kit,but not the hybrid topologies.Further analysis of c-kit using the CD and NMR technique,combined with the unique structural characteristics of c-kit,reveals that the crowding,dehydration and interaction of DMSO are conductive to the formation and stability of the parallel G-quadruplex.The present study suggests that,DMSO,a common solvent used in DNA experiments,may have a nonnegligible influence on the structure and stability of G-quadruplex.

Permeation of dimethyl sulfoxide into articular cartilage at subzero temperatures

Osteochondral allografting has been proved to be a useful method to treat diseased or damaged areas of joint surfaces. Operational long-term stocks of grafts which supply a buffer between procurement and utilization would contribute to the commercialization or industrialization of this technology. Vitrification has been thought to be a promising method for successful preservation of articular cartilage （AC）, but high concentration cryoprotectants （CPAs） are used which may cause high cellular toxicity. An effective way to reduce CPA toxioity is to increase CPA concen- tration gradually while the temperature is lowered. Understanding the mechanism of （31~A permeation at subzero temperatures is important for designing the cryopreservation protocol. In this research, the permeation of dimethyl sulfoxide （MezSO） in ovine AC at subzero temperatures was studied experimentally. Pretreated AC discs were ex- posed in Me2SO solutions for different time （0, 5, 15, 30, 50, 80, and 120 min） at three temperature levels （-10, -20, and -30℃）. The Me2SO concentration within the tissue was determined by ultraviolet （UV） spectrophotometry. The diffusion coefficients were estimated to be 0.85×10-6, 0.48×10-8, and 0.27×10-6 cm2/s at -10, -20, and -,30℃, respectively, and the corresponding activation energy was 29.23 kJ/mol. Numerical simulation was performed to com- pare two Me2SO addition protocols, and the results demonstrated that the total loading duration could be effectively reduced with the knowledge of permeation kinetics.

Dimethyl Sulfoxide Is Feasible for Plant Tubulin Assembly In vitro： A Comprehensive Analysis

Abstract: It is much more difficult for tubulin from plant sources to polymerize in vitro than tubulin from animal sources. Taxol, a most widely used reagent in microtubule studies, enhances plant microtubule assembly, but hinders microtubule dynamics. Dimethyl sulfoxide (DMSO), a widely used reagent in animal microtubule studies, is a good candidate for the investigation of plant microtubule assembly in vitro. However, proper investigation is lacking about the effects of DMSO on plant microtubule assembly in vitro. In the present study, DMSO was used to establish optimal conditions for the polymerization of plant tubulin. Tubulin, purified from lily pollen, polymerizes into microtubules at a critical concentration of 1.2 mg/mL in the presence of 10% DMSO. The polymers appear to have a normal microtubule structure, as revealed by electron microscopy. In the presence of 10% DMSO, microtubule polymerization decreases when the pH of the medium is increased from 6.5 to 7.4. Both the polymerization rate and the mass of the polymers increase as temperature increases from 25 to 40 °C. Tubulin polymerizes and depolymerizes along with cycling of temperature, from 37 to 4 °C, or following the addition to or the removal of Ca2+ from the medium. When incubated with nuclei isolated from tobacco BY-2 suspension cells, tubulin assembles onto the nuclear surface in the presence of 10% DMSO. Labeling lily pollen tubulin with 5- (and 6-) carboxytetramethyl-rhodamine succinimidyl ester (NHS-rhodamine) was performed successfully in the presence of 10% DMSO. Labeled tubulin assembles into a radial structure on the surface of BY-2 nuclei. The polymerization of lily pollen tubulin is also enhanced by microtubule-associated proteins from animal sources in the presence of 10% DMSO. All the experimental results indicate that plant tubulin functions normally in the presence of DMSO. Therefore, DMSO is an appropriate reagent for plant tubulin polymerization and investigation of plant microtubules in vitro.

Measurement and Prediction on the Surface Properties of Dimethyl Sulfoxide/Water Mixtures

Pendent drop method was adopted to measure the surface tension of dimethyl sulfoxide（DMSO）/water mixtures. A new pendent drop apparatus was built up and checked with water, and a good agreement of our data with literature could be found. With the new apparatus, the surface tensions of nine DMSO/water mixtures with mass frac- tions of water from 0.1 to 0.9 were investigated in a temperature range of 298--338 K. The expanded uncertainty for surface tension measurement was estimated to be 0.5% at a confidence level of 95%（k=-2） in the whole temperature range. A thermodynamic-based relation was used to predict the surface properties of DMSO/water mixtures. Based on the relation and Gibbs adsorption theory, a prediction model was proposed for the calculation of surface relative excess and the thickness of the surface molecule layer.

DEVELOPMENT OF A CATALYST FOR SOLUTION OF POLY(VINYL ALCOHOL) IN NON-AQUEOUS MEDIUM

Chloro ethane dimethyl sulfoxide,C_2H_5Cl·DMSO(ECI·DMSO)was prepared by interaction of acrylic acid with conc.Hydrochloric acid in dimethyl sulfoxide(DMSO)and subsequent decarboxylation with H_2O_2 solution.The formation of the compound was confirmed by spectral and analytical methods;the molecular weight was determined by cryoscopic method.The solubility of poly(vinyl alcohol)(PVA)in different solvents or mixed solvents at 40℃,50℃and 60℃temperature in the presence of 0.01% of EC1·-DMSO was determined.It tu...

Coherent Vibrational Dynamics and High-resolution Nonlinear Spectroscopy： A Comparison with the Air/DMSO Liquid Interface

We present a comparative study on the C-H stretching vibrations at air/DMSO （dimethyl sulfoxide） interface with both the free-induction decay （FID） coherent vibrational dynamics and the sub-wavenumber high resolution sum-frequency generation vibrational spectroscopy measurements. In principle the frequency-domain and time-domain spectroscopic measurements should generate identical information for a given molecular system. However, when the molecular systems are with several coupled or overlapping vibrational modes, obtain- ing detailed spectroscopic and coherent dynamics information is not as straightforward and rather difficult from either the time-domain or the frequency domain measurements. For the case of air/DMSO interface that is with moderately complex vibrational spectra, we show that the frequency-domain measurement with sub-wavenumber high-resolution sum-frequency generation vibrational spectroscopy is probably more advantageous than the time- domain measurement in obtaining quantitative understanding of the structure and coherent dynamics of the molecular interface.

Effects of storage media,supplements and cryopreservation methods on quality of stem cells

Despite a vast amount of different methods, protocols and cryoprotective agents(CPA), stem cells are often frozen using standard protocols that have beenoptimized for use with cell lines, rather than with stem cells. Relatively fewcomparative studies have been performed to assess the effects of cryopreservationmethods on these stem cells. Dimethyl sulfoxide (DMSO) has been a key agent forthe development of cryobiology and has been used universally for cryopreservation.However, the use of DMSO has been associated with in vitro and in vivotoxicity and has been shown to affect many cellular processes due to changes inDNA methylation and dysregulation of gene expression. Despite studies showingthat DMSO may affect cell characteristics, DMSO remains the CPA of choice, bothin a research setting and in the clinics. However, numerous alternatives to DMSOhave been shown to hold promise for use as a CPA and include albumin,trehalose, sucrose, ethylene glycol, polyethylene glycol and many more. Here, wewill discuss the use, advantages and disadvantages of these CPAs for cryopreservationof different types of stem cells, including hematopoietic stem cells,mesenchymal stromal/stem cells and induced pluripotent stem cells.

RAT EXOCRINE PANCREATIC SECRETION BYVAGAL STIMULATION OCCURSVIAMULTIPLEMEDIATORS

The vagus is a mixed nerve containing cholinerrgic and non-cholinergic neurons. Vagal fibers interact with peptidergic neurons of the enteric nervous system which stain immunohistochemically for cholecystokinin, vasoactive intestinal polypeptide, and gastrin releasing peptide. The contribution of these peptidergicneurons in the pancreatic response to vagal stimulation is unknown. We tested the effect of specific inhibitor of these stimulants against vagally mediated exocrine secretion in rats. The response to vagal stimulation was blocked significantly by each of the following:the ganglionic blocker hexamethonium (l00% inhibition); the muscarinic, cholinergic blocker atropine (85% inhibition); the specific cholecystokinin-A receptor blocker (91 % inhibition); and a vasoactive intestinal polypeptide polyclonal antibody (89% inhibition). This observation is consistent with the hypothesis that potentiating interactions among several agonists mediate the vagal response. Our study, however, dose not exclude acetylcholine as the final commommediator.

Synthesis and Crystal Structure of Neodymium Complex [Nd(C_6H_4OHCHNC_2H_4NCHC_6H_4OH)(NO_3)_3(CH_3SOCH_3)]

The title complex was obtained by reaction of hydrated neodymium(Ⅲ) nitrate with N,N-disalicyclideneethylenediamine in DMSO. The complex [Nd(C_6H_4OHCHNC_2H_4NCHC_6H_4OH)(NO_3)_3(CH_3SOCH_3)] crystallizes in monoclinic system, space group- P2_1/n, a=9.663(2), b=16.610(6),c=16.322(5),β=102.77(2)°,V=2555(3),M_r=676.71,Z=4,Dx=1.759 gcm-3. The coordination number of Nd(Ⅲ) is 9 with the geometry of a monocapped square antiprism.All of coordination atoms are oxygen atoms from three bidentate nitrate groups, two dischiff base molecules and one DMSO molecule.

Isolation of Fucoxanthin from the Rhizoid of Laminariajaponica Aresch

Fucoxanthin was extracted from the intact rhizoid of Laminariajaponica Aresch with dimethyl sulfoxide （DMSO）, and then recovered from the DMSO extract by partitioning into ethyl acetate and subsequent evaporation. Some isolation conditions such as solvent volume and extraction time were screened. The quantity and quality of the extracted fucoxanthin were determined by spectral analysis （absorption spectra and fluorescence emission spectra）. The results indicated that： （1） the average total content of fucoxanthin was 122.1μg in 1 g of fresh L. japonica rhizoid; （2） in comparison with the widely used organic solvent, acetone, DMSO was much more effective for the extraction of fucoxanthin; （3） both DMSO volume and extraction time influenced extraction efficiency such as the recovery rate and purity of fucoxanthin （1 g of fresh L. japonica rhizoid treated with 4 mL DMSO for 60 min, yielded 〉 88% of the total fucoxanthin with purity 0.63）; （4） when （NH4）2SO4 concentration was in the range of 0.5-1.0 mol/L, the pigments rapidly and entirely moved from DMSO into the ethyl acetate phase; （5） the ethyl acetate and DMSO were recycled using a rotary evaporator.

Productive HBV infection of well-differentiated, hNTCP-expressing human hepatoma-derived(Huh7) cells

Feasible and effective cell models for hepatitis B virus(HBV) infection are required for investigating the complete lifecycle of this virus, including the early steps of viral entry. Resistance to dimethyl sulfoxide/polyethylene glycol(DMSO/PEG), h NTCP expression, and a differentiated state are the limiting factors for successful HBV infection models. In the present study, we used a hepatoma cell line(Hu7^(hDNTCPh)) to overcome these limiting factors so that it exhibits excellent susceptibility to HBV infection. To achieve this goal, different hepatoma cell lines were tested with 2.5% DMSO/4%PEG8000, and one resistant cell line(Huh7 D) was used to construct a stable h NTCP-expressing cell line(Hu7^(hDNTCPh)) using a recombinant lentivirus system. Then, the morphological characteristics and differentiation molecular markers of Hu7^(hDNTCPh) cells with or without DMSO treatment were characterized. Finally, the susceptibility of Hu7^(hDNTCPh) cells to HBV infection was assessed. Our results showed that Huh7 D cells were resistant to 2.5% DMSO/4% PEG8000, whereas the others were not. Hu7^(hDNTCPh) cells were established to express a high level of h NTCP compared to liver extracts, and Hu7^(hDNTCPh) cells rapidly transformed into a non-dividing, well-differentiated polarized phenotype under DMSO treatment. Hu7^(hDNTCPh) cells fully supported the entire lifecycle of HBV infection. This cell culture system will be useful for the analysis of host-virus interactions, which should facilitate the discovery of antiviral drugs and vaccines.

High efficiency bulk heterojunction organic solar cell by using high conductivity modified PEDOT:PSS as a buffer layer

In this paper,bulk heterojunction solar cells with poly-(3-hexylthiophene)(P3HT):[6,6]-phenyl-C61-butyric-acid-methylester(PCBM) as an active layer and modified poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS) as a buffer layer are fabricated.The buffer layer is modified by adding 1% to 5% dimethyl sulfoxide(DMSO) into PEDOT:PSS solution before spin-coating.The conductivity of modified PEDOT:PSS and the performance of solar cells with modified PEDOT:PSS are measured.The highest conductivity of modified PEDOT:PSS with 4% DMSO can achieve 89.693 S/cm.The performance of organic solar cell with PEDOT:PSS modified by 4% DMSO is the best.The 4% DMSOmodified-PEDOT:PSS cell has a power conversion efficiency of 3.34%,V oc of 5.7 V,J sc of 14.56 mA/cm 2 and filling factor(FF) of 40.34%.

Contraception with RISUG and functional reversal through DMSO and NaHCO3 in male rabbits

The study aimed to evaluate reversal of short- and long-term vas occlusion with reversible inhibition of sperm under guidance （RISUG） using dimethyl sulfoxide （DMSO） and sodium bicarbonate （NaHCO3） in male rabbits （Oryctolagus cuniculus）. Animals were divided into seven groups containing five animals each. Fortnightly, semen analysis revealed that sperm concentration and output steadily declined after vas occlusion and complete azoospermia was attained at 30-60 days postinjection. Spermatozoa reappeared at 60-75 days of reversal and normozoospermia was noticed between 135 days and 150 days in the reversal groups. All spermatozoa were found nonmotile prior to azoospermia and a gradual recovery in sperm motility was observed between 105 days and 135 days of reversal. A significant decline in viability of sperms was noticed during vas occlusion up to 30-60 days which recovered at 60-75 days postreversal and normalized by 75-105 days in the reversal groups. A significant enhancement in the sperm abnormalities was recorded in all vas occluded animals as well as those in initial periods of reversal. Other parameters, namely, semen volume, ejaculation time, pH, color, and consistency, remained unaltered during all phases of the study. Fertility test, at the intervals of 15 days, demonstrated that animals exhibited complete sterility during the entire period of vas occlusion. A gradual recovery in fertility was observed with the appearance of spermatozoa following vas occlusion reversal and 100% fertility was observed following 135-150 days of reversal. F, progeny of reversed animals was found normal. The results suggest that reversal with DMSO or NaHCO3 is feasible, with normal progeny, following short- and long-term contraception.

Ultrafast third-order optical nonlinearities in DMSO

The third-order optical nonlinearities of dimethyl sulfoxide （DMSO） are investigated using the optical Kerr effect （OKE） and Z-scan techniques with femtosecond pulses. We are able to fit the OKE signal theoretically by convolving the autocorrelation of the incident pulse intensity profile with the impulse responses of the samples, illustrating the instantaneous nonlinear response of DMSO. We verify that the purely electronic cloud distortion causes the observed signal for DMSO. The Z-scan technique is used to estimate the third-order susceptibility of DMSO, which is about a quarter of that for CS2 and mainly comes from the nonlinear refraction with an intensity of less than 140 GW/cm^2.