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The study explains the preparation of spherical agglomerates (SA) of telmisartan (TLS), a BCS class II drug used to improve it's physicochemical and bulk properties. Drugs of this class could potentially exhibit dissolution rate limited absorption. TLS spherical agglomerates were designed using hydrophilic polymer (PVP K-30), dimethyl formamide (DMF), water and ethyl acetate (bridging liquid) by solvent change method and evaluated for micromeritic properties. The SA were characterized by particle size determination, FTIR, PXRD and SEM. The results of micromeritic studies indicated that SA showed improved flow properties due to their spherical shape and bigger size. Absence of strong interaction at molecular level and alteration in the crystal structure of TLS with modification in crystallinity was confirmed by FTIR and PXRD respectively. TLS solubility characteristics were improved by this approach. [ABSTRACT FROM AUTHOR]

The CeCuOx composite catalysts for the catalytic conversion of dimethyl formamide were prepared and catalyzed by the sol-gel method with a controlled amount of Cu. The physical and chemical properties and catalytic performance of the CeCuOx composite catalysts were characterized by X-ray diffraction analysis, N2 adsorption-desorption, scanning electron microscopy, X-ray photoelectron spectroscopy, and H2-programmed step-up reduction. The results indicate that the doping of Cu increases the particle size of the CeOx support and enhances the relative content of Ce3+ species on the CeOx surface. The Cu/Ce ratio significantly influences the activity, product selectivity, and stability of the composite catalyst. Among them, Cu80Ce20 exhibits the best overall performance in the catalytic reaction of dimethylformamide. [ABSTRACT FROM AUTHOR]

Silicon nanoparticles (SiNPs) show tunable photoluminescence (PL), water-dispersibility, high photostability, and low cytotoxicity, thus constituting promising candidates for bioimaging applications. Because SiNP PL depends finely on particles' crystallinity and surface composition, specific tuning of PL properties has remained elusive. Herein, using steady and time-resolved PL studies, absorbance spectroscopy, and electrochemical techniques, we have deeply analyzed the origin of the PL of SiNPs obtained from a wet chemical synthesis procedure based on the oxidation of Zintl salts in dimethyl formamide (DMF). Obtained SiNPs, surface-functionalized with propylamine terminal groups, were amorphous and 2.8–3.7 nm in size. The photophysical evidence, together with XPS and FTIR spectroscopy, supported a core–shell structure of the nanoparticles consisting of a silicon core surrounded by a 0.7–1.25 nm-thick oxidized silicon shell containing low concentrations of trapped iminium siloxyl ions Cl−(CH3)2N+=CH−O−Si or related compounds. The introduction of N-functionalities in the nanoparticle shell was assigned to the reaction of Si–Cl and Si–H bonds formed during synthesis, with DMF. The use of increasing amounts of NH4Cl in the synthesis procedure led to more oxidized shell structures of SiNPs. It is suggested that the presence of an oxidized silicon shell containing trapped iminium siloxyl ions provided a high density of localized states capable of quenching the core-state emission and of being themselves populated by absorption of visible light. Moreover, it was experimentally confirmed that emission preferentially takes place from localized states introduced by O-functionalities with a high quantum efficiency (ηPL‑trap ≅ 1). As fluorophores, the obtained SiNPs display tunable PL emission and an important red-edge shift, allowing the selection of the PL by changing the excitation wavelength without modification of its chemical composition and size, thus meeting the needs of various types of biosensing methods. [ABSTRACT FROM AUTHOR]

Functionalised multi‐walled carbon nanotubes (MWCNTs) are exclusively used in antibacterial activity due to their high aspect ratio and surface penetration characteristics. This study reports the synthesis of piperazine and dopamine functionalised MWCNTs to investigate antibacterial activity against strains like Staphylococcus aureus and Micrococcus luteus. MWCNTs were activated through acid oxidation and then refluxed at 75°C for 10 and 8 h in the presence of piperazine and dopamine, respectively. The functionalised MWCNTs were characterised by scanning electron microscopy, Fourier‐transform infrared spectroscopy, X‐ray diffraction and Raman spectroscopy. Moreover, functionalised MWCNTs were subjected to zone inhibition assay on agar plates. Results revealed the significant antibacterial activity against various bacteria up to 50%. Similarly, it was observed that the effect of different solvents, such as dimethyl formamide (DMF) and dimethyl sulfoxide (DMSO) was non‐prevalent to the bacterial zone of inhibition. Such facile nano‐modifications provide passage to nano‐antibacterials for advanced studies. [ABSTRACT FROM AUTHOR]

Abstract: A novel transition‐metal free synthetic strategy has been developed for the direct synthesis of 2‐formylarylsulphonate from aryne precursor. The reaction proceeds via CO and C−C bond cleavage as well as C−O,C−C and O−S bond formations in a single reaction vessel. The methodology provides good yield of 2‐formylarylsulphonates and tolerates variety of functional groups. The strategy opens a new avenue for the direct synthesis of ortho‐hydroxyl‐protected aryl aldehydes in organic synthesis. [ABSTRACT FROM AUTHOR]

In this study, microwave assisted degradation of lignin, a paper industry and biorefinery waste product, is investigated in presence of different organic solvents such as ethylene glycol (EG), dimethyl sulfoxide (DMSO) and dimethyl formamide (DMF) at different temperatures (100–140 °C) and treatment periods (20–80 min). Experiments performed in batch microwave reactor revealed that, in all the solvents, a major reduction in weight average molecular weight (M w ) of lignin was observed in the time period of 20–40 min. In a polar protic solvent with high loss tangent (EG), maximum reduction in M w was observed at 120 °C, while in polar aprotic solvents (DMSO and DMF), M w decreased with increase in temperature. Significant yield of phenolics (20 wt.%) containing acetosyringone, guaiacol, syringaldehyde, anisole and lignin dimers (m/z 306, 322 Da) was obtained at 100 °C in DMF and DMSO, while at 140 °C, 11 wt.% phenolics were obtained in EG. Plausible reactions for the formation of phenolic monomers and dimers include etheric C β O and C α C β bond cleavages induced by solvent interactions. The shift of molecular weight distribution to higher molecular weights suggested the involvement of recombination reactions at long treatment periods. This study shows that solvent-assisted microwave processing is a promising technique to convert lignin to phenols. [ABSTRACT FROM AUTHOR]

The stability of a compound in the solvent in which it is dissolved is a fundamental parameter in medicinal chemistry. In this article, we report on the results of our investigations on the stability of five Ir(III) complexes in DMF and DMSO. Importantly, we demonstrate that the rate of ligand exchange/decomposition of these compounds has an influence on their in vitro anticancer properties. The compounds were generally found to be less toxic to cancer cells after having been dissolved for longer time (24 h) in DMSO compared to short incubation time (1 h) in the same solvent. On the contrary, only minor differences in cytotoxicity were observed when the compounds were dissolved in DMF, emphasizing that this solvent should be employed instead of DMSO when unstable compounds are investigated, provided that the concentration of DMF is kept at a low concentration level. [ABSTRACT FROM AUTHOR]

The specific adsorption of chloride ions on the renewable liquid (Cd-Ga) electrode from mixed [0.1 М LiCl + 0.1(1-) М LiBF] solutions in dimethyl formamide (DMF) is studied with an ac bridge at the following fractions of surface-active anion m: 0, 0.01, 0.02, 0.05, 0.1, 0.2, 0.5 and 1. It is found that the data on the specific adsorption of Cl anion in the system can be quantitatively described by Frumkin's isotherm. The free adsorption energy of Cl (Δ G ) is a quadratic function of electrode charge. The results are compared with the corresponding data for the Ga/DMF and (In-Ga)/DMF interfaces. It is shown that the adsorption energy of Cl-anions at the metal/DMF interface depends on the metal nature and increases in the series (In-Ga) ≈ (Cd-Ga) < Ga. The energy of metal-DMF chemisorption interaction, which hampers ion adsorption, increases in the same series. The analysis of the data uniquely indicates that the free energy of metal-Cl interaction (Δ G ) increases in the series (In-Ga) ≈ (Cd-Ga) < Ga. Thus, in the series of electrodes studied, the variations in the energies of metal-Cl and metal-DMF specific interaction are correlated: the higher the energy of metal-DMF chemisorption interaction, the higher the energy of metal interaction with Cl. [ABSTRACT FROM AUTHOR]

Comparision between pulping of canola stalks with dimethyl formamide and diethylene glycol was studied in order to investigate the effects of cooking temperature (190˚C, 210˚C, and 230˚C), cooking time (120 min, 150 min, and 180 min) and dimethyl formamide or diethylene glycol (50%, 60%, and 70%) on the properties of pulp and paper. SCAN viscosity was applied to estimate the extent of cellulose degradation. Responses of pulp and handsheet properties to the process were analyzed using statistical software (MINITAB 15). The results showed that DMF pulp of canola was better than DEG pulp of Canola under the same conditions of cooking and organosolv ratio. In DMF pulping and DEG pulping, cooking temperature is a significant factor affecting paper properties. Analysis of results revealed that DMF pulp canola obtained at 230 °C, 180 min, and 70% DMF had a low kappa number (25) , indicating that the desired properties of the final product dictated the optimized pulping conditions.

Equine semen are far less tolerant in the freezing and thawing process than bull semen. The stallion spermatozoa are known susceptible to cold-shock relating with the content of their fatty acid on the plasma membrane. The extender is one of determining factors in the success of stallion semen cryopreservation, as an energy source and protector the cell from harmfull effect of cold shock. The common cryoprotective agent (CPA) for mammalian spermatozoa was glycerol, but for stallion semen cryopreservation, dimethyl formamide (DMF) was more suitable. This research was conducted to compare the success of the stallion semen cryopreservation in skim milk and dimitropoulos (DV) extender with DMF as cryoprotectant. Semen from three sexualy mature stallions was collected twice a week using an artificial vagina. Semen was evaluated macro- and microscopically and then divided into two tubes, diluted each of them with skim milk dan DV extender (1:1), centrifuged at 3 000 rpm for 15 minutes. The supernatant was removed and the pellet (spermatozoa) was re-diluted in skim DMF (SDMF) and DVDMF extender with the concentration of spermatozoa was 200x106 ml-1. The semen then packed in 0.3ml minitub straw equilibrated for two hours at 4-5oC and frezee in liquid N2 vapor for 10 minutes. The assessment of sperm quality was conducted based on the percentage of sperm motility and viability. In this research, post-thawed semen in DVDMF showed the percentages of the motility (36.2%) and the viability (59.3%) higher (P

The efficacy of three extenders, tris-egg yolk-5% ethylene glycol (T1), lactose-egg yolk-5% ethylene glycol (T2) and lactose-egg yolk-5% dimethyl formamide (T3) on preserving the viability of post-thawing canine spermatozoa was evaluated. Three ejaculates per dog were obtained of five animals. The semen was packaged in 0.5ml straws and cooled to 4°C for 120min. The straws were frozen 4cm above the nitrogen level for 15min and thawed in water-bath at 37°C for 60sec and at 75°C for 7sec. Progressive motility and vigour were evaluated immediately after thawing (time 0) and at 30, 60, 90 and 120min. Structural and functional integrity of plasma membrane of the spermatozoa were evaluated, respectively, by fluorescent staining probes and hypoosmotic swelling test. Lactose-egg yolk based extenders showed better cryoprotectant capability and dimethyl formamide was an alternative cryoprotectant agent for dog sperm cells.Avaliou-se a eficácia de três diluidores, tris-gema com 5% de etileno glycol (T1), lactose-gema com 5% de etileno glicol (T2) e lactose-gema com 5% de dimetil-formamida (T3) na criopreservação do sêmen de cães. Foram obtidos três ejaculados por cão de um total de cinco animais. O sêmen foi envasado em palhetas de 0,5ml e resfriado até 4°C por 120min. As palhetas foram congeladas 4cm acima do nitrogênio líquido por 15min e descongeladas em banho-maria a 37°C por 60seg e 75°C por 7seg. A motilidade progressiva e o vigor foram avaliados imediatamente após a descongelação (tempo 0) e aos 30, 60, 90 e 120min. A integridade estrutural e funcional da membrana plasmática do espermatozóide foi avaliada, respectivamente, por meio da coloração de fluorescência e pelo teste hiposmótico. Os diluidores à base de lactose gema foram mais eficazes em preservar a viabilidade espermática pós-descongelação e a dimetil-formamida é um crioprotetor eficaz para espermatozóides de cães.

In this study investigating the effect of immobilized cells on dimethyl formamide (DMF) biodegradation, the performance of a mixed-bed biofilm reactor (MBBR) was evaluated with an activated-sludge reactor (AS). MBBR and AS bioreactors could biodegrade 9000 mg/1 COD of feed DMF with DMF removal efficiencies of 55.6% and 43.6%, respectively, after 7 days. In the next step, when nitrifying microorganisms were fed to the AS bioreactor, then coupled with MBBR, 50% of the treated wastewater of this coupled bioreactor was recycled to the feed point, with the DMF removal efficiency of the coupled bioreactor for 12,000 mg/1 COD reaching 94.17% after 10 days. In contrast to MBBR and AS bioreactors being used by themselves (as opposed to together), which tends to increase pH due to the ammonia produced during DMF biodegradation, in a coupled bioreactor the completed nitrification process caused reduction of more than 98.80% of the ammonia, with the pH remaining neutral as a result. Furthermore, the concentration of microorganisms stayed stable for all organic loading rates. During this experiment, the thickness of biofilm increased gradually at the rate of 1.2, 0.13, and 0.36 μm per day in batch phase, continuous phase in MBBR, and coupled bioreactor, respectively. [ABSTRACT FROM AUTHOR]

Some Schiff bases of pyrazole and 4-amino antipyrine have been synthesized. The antibacterial screening of these synthesized compounds was done in dimethyl formamide against four Gram positive bacteria viz. Bacillus cereus, Staphylococcus aureus, Staphylococcus epidermidids and Micrococcus luteus, and three Gram negative bacteria viz. Proteus mirabilis, Escherichia coli and Klebsiella aerogenes. It is observed that in comparison to Schiff bases of 4-amino antipyrine, pyrazole Schiff bases are better for inhibition for these selected Gram positive and Gram negative bacterial strains. [ABSTRACT FROM AUTHOR]

Mesoporous carbon (MC) was prepared in soft template, and potassium ferricyanide was added into MC to prepare the modified mesoporous carbon (MMC). TEM, SEM, FT-IR, and N adsorption-desorption were used to characterize the textural properties of mesoporous materials. The BET specific surface area, pore volume, and the pore size of MC and MMC were 607.6321 and 304.7475 m/g, 0.313552 and 0.603573 cm/g, and 5.4356 and 7.9227 nm, respectively. The adsorption capabilities of MC and MMC were compared with the silica mesoporous material MCM-41. The influences of different adsorption conditions were optimized. For MC, the optimums of adsorbent dose, DMF initial concentration, rotating speed, and pH were 0.002 mg/50 mL, 200 mg/L, 200 r/min, and 4, respectively. MMC showed the highest DMF adsorption capacity at adsorbent dose 0.002 g/50 mL, DMF initial concentration 1000 mg/L, rotating speed 1000 r/min, pH more than 9, and contact time of less than 20 min. Meanwhile for MC, MMC, Pseudo-second-order equation was used to fit adsorption kinetics data. And adsorption process could be well fitted by Langmuir and Freundlich adsorption isotherms of MC, MMC. The results showed that MMC was a perfect adsorbent for DMF, and it was easy to separation and recycle. The recycling property of MMC was still relatively better than other two adsorbents. [ABSTRACT FROM AUTHOR]

O objetivo neste trabalho foi avaliar os efeitos da dimetil-formamida na criopreservação de sêmen caprino, por meio de testes in vitro. As partidas de sêmen foram congeladas com os diluidores leite desnatado-gema, associado a diferentes crioprotetores e concentrações: 7% de glicerol (T1); 3,5% de glicerol e 3,5% de dimetil-formamida (T2) e 5% de dimetil-formamida (T3). O sêmen foi centrifugado e envasado em palhetas de 0,5 mL, sendo resfriado por 40 minutos, atingindo 5,0°C e permanecendo nesta temperatura por mais 1 hora e 20 minutos. Os parâmetros avaliados in vitro foram a motilidade progressiva e o vigor espermático, a integridade acrossômica, a integridade da membrana plasmática (HO) e a reação acrossômica. Observou-se perda de 30,0% da motilidade inicial quando as amostras foram submetidas aos procedimentos de criopreservação. A perda de integridade da membrana plasmática, avaliada pelo teste hiposmótico (HO) foi de 19%. As lesões de acrossoma aumentaram em 3% durante o teste de termo-resistência (TTR) lento. Não houve diferença entre os tratamentos quanto aos aspectos de motilidade nos tempos de 0,00; 0,05; e 1,00 horas do TTR e vigor em todos os tempos. No tempo de 2,00 horas do TTR, registrou-se diferença entre os tratamentos 1 e 2, de modo que a motilidade no tratamento 2 foi superior às demais. Os valores de integridade de membrana plasmática, integridade acrossômica e reação acrossômica pós-descongelamento não diferiram entre os tratamentos, indicando que a dimetil-formamida não foi superior ao glicerol na manutenção da qualidade espermática após a criopreservação.The objective of this trial was to evaluate the efficiency of dimethylformamide on cryopreservation of goat semen using semen physical analyses and complementary tests. Alpine and Saanen bucks from the Dairy Goat Experimental Station- DZO were used. Semen samples were frozen with a yolk-skimmed milk diluent and cryoprotectors with different concentrations as follows: 7% glycerol (T1), 3.5% glycerol plus 3.5% dimethylformamide (T2) or 5% dimethylformamide (T3). Semen was centrifuged, diluted, and bottled in 0.5 mL straws followed by cooling for 40 minutes until reach 5.0°C and kept at this temperature for additional 80 minutes. Samples were then exposed to liquid nitrogen vapor for 15 minutes and finally frozen. Thawing was done in a waterbath at 37°C for 50 seconds. The following variables were evaluated in vitro: sperm progressive motility and vigor, acrosomal integrity and reaction, and plasmatic membrane integrity. The cryopreservation procedures reduced 30.0% of the initial motility and 19% of plasmatic membrane integrity that was evaluated using the hyposmotic swelling test (HOST). It was observed an increaseof 3% in acrosomal lesions when samples were submitted to a slow thermoresistance test (TRT). No significant differences in sperm motility were observed among treatments at 0, 5, and 60 minutes of TRT as well as in sperm vigor at all TRT times. However, at 120 minutes of TRT a significant difference in sperm motility was found comparing T1 and T2 while T3 was intermediate. There were no significant differences on plasmatic membrane integrity, acrosomal integrity, and post-thawing acrossomal reaction across treatments. It can be concluded that dimethylformamide can be a viable alternative for goat semen cryopreservation used alone or in association with glycerol.

The differential capacitance curves were measured with an ac bridge in the (In-Ga)/[DMF + 0.1 m M LiCl + 0.1(1- m) M LiClO], (In-Ga)/[DMF + 0.1 m M LiBr + 0.1(1- m) M LiClO], and (In-Ga)/[DMF + 0.1 m M LiI + 0.1(1- m) M LiClO] (DMF is dimethyl formamide) systems at the following fractions m of surface-active anion: 0, 0.01, 0.02, 0.05, 0.1, 0.2, 0.5, and 1. The data on the specific adsorption of Cl, Br, and I anions in these systems can be quantitatively described by the Frumkin's isotherm. The free energy of Cl, Br, and I adsorption (Δ G) is a quadratic function of electrode charge. It is found that, at the (In-Ga)/DMF interface, as well as at the Ga/DMF interface, Δ G varies in the series I < Br < Cl. An analysis indicates conclusively that the series of surface activity of halide ions is reversed when we pass from the Hg/DMF and Bi/DMF interfaces to the Ga/DMF and (In-Ga)/DMF interfaces. A change of the solvent in the transition from (In-Ga)/ N-methyl formamide interface to the (In-Ga)/dimethyl formamide interface is also accompanied by the transition from the common to the reversed series of surface activity of halide ions. [ABSTRACT FROM AUTHOR]

Nanostructured polyaniline was prepared using the template method in the mixed solvent that was composed of dimethyl formamide and distilled water. A series of tests were performed to examine the structural and electrical performance of polyaniline, including X-ray diffraction, scanning electron microscopy, Fourier-transform infrared spectrometry, nitrogen adsorption-desorption, cyclic voltammetry and galvanostatic charge-discharge tests. Results indicated that the mixed solvent could lead to a different morphology and influence the electrical performance of polyaniline in the system. The specific surface area of polyaniline was greatly improved and the electrical properties were enhanced correspondingly. [ABSTRACT FROM AUTHOR]

The differential capacitance curves were measured with an ac bridge in the Ga/[DMF + 0.1 m M LiBr + 0.1(1 − m) M LiClO] and Ga/[DMF + 0.1 m M LiI + 0.1(1 − m) M LiClO] systems at the following fractions m of surface-active anion: 0, 0.01, 0.02, 0.05, 0.1, 0.2, 0.5, and 1. Dimethyl formamide (DMF), as well as N-methyl formamide ( N-MF), enables one to realize considerable positive charges of Ga electrode, at which it remains ideally polarizable (up to 11 μC/cm). The data on the specific adsorption of Br and I anions in these systems can be quantitatively described by the Frumkin's isotherm. The free energy of Br and I adsorption Δ G is a quadratic function of electrode charge. It is found that, at the Ga/DMF interface, Δ G varies in the series I < Br < Cl. It is shown that the series of surface activity of halide ions is reversed when we pass from Hg/DMF and Bi/DMF interfaces to Ga/DMF interface. In contrast to the Ga/ N-MF interface, where the values of Δ G for Br and I were almost equal and an increase in Δ G for Cl was rather small, at the Ga/DMF interface, Δ G increases significantly in the series I < Br < Cl. [ABSTRACT FROM AUTHOR]

The differential capacitance curves were measured with an ac bridge in the Ga/[DMF + 0.1 m M LiCl + 0.1(1 − m) M LiClO] system at the following fractions m of surface-active anion: 0, 0.01, 0.02, 0.05, 0.1, 0.2, 0.5, and 1. Dimethyl formamide (DMF), as well as N-methyl formamide ( N-MF), enables one to realize large positive charges of Ga electrode, at which it remains ideally polarizable (up to 12 μC/cm). It is found that the data on the specific adsorption of Cl anion in the system can be quantitatively described by the Frumkin's isotherm. The free energy of Cl ion adsorption Δ G is a quadratic function of electrode charge. It is shown that, on the Ga electrode, the transition from N-methyl formamide to dimethyl formamide is accompanied by a significant increase in the free adsorption energy Δ G. In view of a stronger Ga-DMF interaction as compared with Ga-( N-MF), this result can be explained only by the corresponding decrease of salvation energy of chloride ion. [ABSTRACT FROM AUTHOR]

In this study, solution electrospinning of neat Polycaprolactone (PCL) and Polycaprolactone - Carbon nanotube (CNT) nanocomposite using Dimethyl formamide (DMF) as a single solvent was performed. The emphasis of this study was to optimize the electrospinning process parameters for different types of collector i.e. flat plate and rotating disc. It is observed that the change in collector type affects the morphology of the deposited nanofibres and with increasing speed of the rotating collector, the alignment of nanofibres increases. Additionally an increase in conductivity of PCL - CNT nanocomposite dope was observed which lead to the formation of beadless nanofibre vis-a-vis neat PCL nanofibres where the beads were observed under the same conditions. [ABSTRACT FROM AUTHOR]

The reaction of 7-phenyl-7 H-pyrazolo[3,4- d][1,2,3]triazin-4-ol with thionyl chloride has been studied in the presence and absence of dimethyl formamide. It was found that heating the compound with thionyl chloride in the absence of dimethyl formamide gave 5-amino-1-phenyl-1 H-pyrazole-4-carboxylic acid chloride and in its presence a mixture of 5-chloro- N-formyl-1-phenyl-1 H-pyrazole-4-carboxamide, 5-chloro-1-phenyl-1 H-pyrazole-4-carboxamide, and 4-chloro-6-(5-chloro-1-phenyl-1 H-pyrazol-4-yl)-1-phenyl-1 H-pyrazolo[3,4- d]pyrimidine. [ABSTRACT FROM AUTHOR]

Abstract: Experimental investigations have been carried out to study heat and mass transfer characteristics of Tetrafluoro ethane (R134a) in Dimethyl formamide (DMF) solution in a compact bubble absorber of vapour absorption refrigeration system of 1 TR capacity. Plate heat exchangers have been used as system components. Bubble absorption principle is employed in the absorber and hot water supplies heat to the generator. Effect of operating parameters such as circulation ratio, absorber and generator temperatures on heat and mass transfer effectiveness, overall heat transfer coefficient and volumetric mass transfer coefficient are investigated. It is found that heat and mass transfer effectiveness of absorber are better at lower circulation ratios and higher generator temperatures. Experimental results are compared with those obtained from numerical model developed earlier by the authors and the agreement is generally fair. From the experimental data, a correlation has been obtained for volumetric mass transfer coefficient, using multi-linear regression analysis. [Copyright &y& Elsevier]

Abstract: Cryopreserved, sex-sorted stallion sperm has been shown to have poor fertility. During this study, the effects of cryoprotectant (glycerol [GLY] and dimethyl formamide [DMF]), cryoprotectant equilibration time (0, 30, 60, 90, or 120 minutes), and cryoprotectant concentration (2%, 3%, or 4% vol/vol) on stored sex-sorted and stored nonsorted stallion sperm were evaluated. Total motility, viability, and DNA integrity (determined using sperm chromatin structure assay) of sperm were assessed after thawing. Equilibration for 90 minutes improved total motility (33.8%) compared with 0 (28.5%) or 120 minutes (29.8%; P < 0.05), though viability was higher after 120 minutes (33.1%) compared with 0 (30.5%) or 30 minutes (31.0%; P < 0.01). The viability of nonsorted sperm decreased as cryoprotectant concentration increased (P < 0.001), and total motility of nonsorted sperm was higher when DMF alone was used (15.8%, 16.6%, and 24.0% for GLY, GLY and DMF, and DMF respectively; P < 0.001). Sex sorting was detrimental to the postthaw quality of sperm; at 45 minutes after thawing, total motility of nonsorted sperm was higher than that of sex-sorted sperm (37.4% vs. 5.6%; P < 0.001), the viability of sex-sorted sperm was lower than that of nonsorted sperm (12.4% vs. 30.0%; P < 0.001, averaged over postthaw time), and sex-sorted sperm had higher detectable DNA fragmentation index (DFI) (63.6% vs. 11.3%, P < 0.001) and mean DFI (285.1 vs. 211.3, P < 0.001) than nonsorted sperm. The viability of sex-sorted sperm was improved by GLY and DMF or DMF compared with GLY (22.6%, 25.3%, and 19.3%, respectively; P < 0.05), and the DNA integrity of sex-sorted sperm was improved by the use of DMF compared with GLY (detectable DFI, 60.2 vs. 66.8, P < 0.05; and mean DFI, 280.9 vs. 289.2, P < 0.05, respectively). In conclusion, postthaw characteristics of stored sex-sorted and stored nonsorted stallion sperm were improved by the use of DMF as a cryoprotectant, though the parameters to benefit differed between sorted and nonsorted sperm. [Copyright &y& Elsevier]