Carnitine/organic cation transporter OCTN2-mediated transport of carnitine in primary-cultured epididymal epithelial cells

Carnitine is essential for the acquisition of motility and maturation of spermatozoa in the epididymis, and is accumulated in epididymal fluid. In this study, carnitine transport into primary-cultured rat epididymal epithelial cells was characterized to clarify the nature of the transporter molecules involved. Uptake of carnitine by primary-cultured epididymal epithelial cells was time, Na(+) and concentration dependent. Kinetic analysis of carnitine uptake by the cells revealed the involvement of high- and low-affinity transport systems with Km values of 21 microM and 2.2 mM respectively. The uptake of carnitine by the cells was significantly reduced by inhibitors of carnitine/organic cation transporter (OCTN2), such as carnitine analogues and cationic compounds. In RT-PCR analysis, OCTN2 expression was detected. These results demonstrated that the high-affinity carnitine transporter OCTN2, which is localized at the basolateral membrane of epididymal epithelial cells, mediates carnitine supply into those cells from the systemic circulation as the first step of permeation from blood to spermatozoa.     

Transport of organic acid anions and guanosine into vacuoles of Saccharomyces pastorianus

Isolated vacuoles of the yeast Saccharomyces pastorianus accumulate citrate, α-ketoglutarate, malate and guanosine. This accumulation is Mg ATP-dependent and inhibited by protonophores. The ionophores monensin and A23187 (electroneutral Meⁿ⁺/nH⁺-exchange) inhibit guanosine accumulation but fail to block citrate uptake. Mg²⁺ ions (2 mM ) increase the values of both Δ$ \tilde \mu $H⁺ components and stimulate the uptake of all the above compounds. Ca²⁺ ions (1 mM ), hyperpolarizing the yeast vacuolar membrane and dissipating the pH gradient, inhibit guanosine uptake and stimulate that of citrate. It is concluded that guanosine is transported into yeast vacuoles by an H⁺/guanosine antiporter while citrate, malate and α-ketoglutarate are translocated by a uniporter(s) at the expense of the membrane potential (positive inside).     

Selective sorption of lead, cadmium and zinc ions by a polymeric cation exchanger containing nano-Zr(HPO3S)2

A novel polymeric hybrid sorbent, namely ZrPS-001, was fabricated for enhanced sorption of heavy metal ions by impregnating Zr(HPO3S)2 (i.e., ZrPS) nanoparticles within a porous polymeric cation exchanger D-001. The immobilized negatively charged groups bound to the polymeric matrix D-001 would result in preconcentration and permeation enhancement of target metal ions prior to sequestration, and ZrPS nanoparticles are expected to sequester heavy metals selectively through an ion-exchange process. Highly effective sequestration of lead, cadmium, and zinc ions from aqueous solution can be achieved by ZrPS-001 even in the presence of competing calcium ion at concentration several orders of magnitude greater than the target species. The exhausted ZrPS-001 beads are amenable to regeneration with 6 M HCI solution for repeated use without any significant capacity loss. Fixed-bed column treatment of simulated waters containing heavy metals at high or trace levels was also performed. The content of heavy metals in treated effluent approached or met the WHO drinking water standard.     

硅胶负载硫酸铁催化合成2-庚基-1,3-二噁戊烷

以正辛醛和乙二醇为原料,以硅胶负载硫酸铁[Fe2(SO4)3/SiO2]为催化剂,合成了2-庚基-1,3-二噁戊烷,考察了醛醇摩尔配比、反应时间、催化剂用量及其稳定性对产率的影响。实验表明,硅胶负载硫酸铁是合成2-庚基-1,3-二噁戊烷的理想催化剂,较优反应条件为正辛醛0.1mol、n(正辛醛)/n(乙二醇)=1.0/1.2(mol/mol)、催化剂的用量为反应物总质量的2.0%、带水剂环己烷12mL、回流反应4.0h,2-庚基-1,3-二噁戊烷的产率可达92.0%以上。     

微乳液溶剂热法微/纳米草酸钐的合成与表征

采用微乳液溶剂热法,在CTAB/正辛烷/正丁醇/硝酸钐水溶液（草酸钾水溶液）所形成的反相微乳液体系中,合成不同尺寸的棒状微/纳米Sm2（C2O4）3.利用X射线衍射（XRD）、透射电子显微镜（TEM）、扫描电子显微镜（SEM）对Sm2（C2O4）3的形貌和尺寸进行了表征.结果表明,微/纳米Sm2（C2O4）3的尺寸随着水与CTAB的摩尔比（ω）、反应时间的增大而增大.     

Visible light Cr(VI) reduction and organic chemical oxidation by TiO2 photocatalysis

Here we report the simultaneous Cr(VI) reduction and 4-chlorophenol (4-CP) oxidation in water under visible light (wavelength > 400 nm) using commercial Degussa P25 TiO2. This remarkable observation was attributed to a synergistic effect among TiO2, Cr(VI), and 4-CP. It is well known that TiO2 alone cannot remove either 4-CP or Cr(VI) efficiently under visible light. Moreover, the interaction between Cr(VI) and 4-CP is minimal if not negligible. However, we found that the combination of TiO2, Cr(VI), and 4-CP together can enable efficient Cr(VI) reduction and 4-CP oxidation under visible light. The specific roles of the three ingredients in the synergistic system were studied parametrically. It was found that optimal concentrations of Cr(VI) and TiO2 exist for the Cr(VI) reduction and 4-CP oxidation. Cr(VI) was compared experimentally with other metals such as Cu(ll), Fe(lll), Mn(IV), Ce(IV), and V(V). Among all these metal ions, only Cr(VI) promotes the photocatalytic oxidation of 4-CP. The amount of 4-CP removed was directly related to the initial concentration of Cr(VI). The system was also tested with four other chemicals (aniline, salicylic acid, formic acid, and diethyl phosphoramidate). We found that the same phenomenon occurred for organics containing acid and/or phenolic groups. Cr(VI) was reduced at the same time as the organic chemicals being oxidized during photoreaction under visible light. The synergistic effect was also found with pure anatase TiO2 and rutile TiO2. This study demonstrates a possible economical way for environmental cleanup under visible light.     

Roosters affected by epididymal lithiasis present local alteration in vitamin D3, testosterone and estradiol levels as well as estrogen receptor 2 (beta) expression

Epididymal lithiasis is a reproductive dysfunction of roosters that is associated with loss of fertility and is characterized by the formation of calcium stones in the lumen of the efferent ductules of the epididymal region. The efferent ductules of birds are responsible for the reabsorption of the fluid coming from the testis as well as luminal calcium. It has been hypothesized that the epididymal stone formation may be related to the impairment of local fluid or calcium homeostasis, which depends on hormones such as estradiol (E(2)). Therefore, this study aimed to investigate possible alterations in the expression of ERα (ESR1) and ERβ (ESR2) in the epididymal region of roosters affected by epididymal lithiasis. The study was performed by immunohistochemistry and western blotting assays. In addition, the concentrations of E(2), vitamin D3, and testosterone, which are also key hormones in maintenance of calcium homeostasis, were determined in the plasma and epididymal region, by ELISA. It was observed that ESR2 expression is increased in all segments of the epididymal region of affected roosters, whereas ESR1 levels are not altered. Moreover, the hormone concentration profiles were changed, as in the epididymal region of roosters with lithiasis the E(2) levels were increased and vitamin D3 as well as testosterone concentrations were significantly decreased. These results suggest that a hormonal imbalance may be involved with the origin and progression of the epididymal lithiasis, possibly by affecting the local fluid or calcium homeostasis.     

Identification of novel dietary phytochemicals inhibiting the efflux transporter breast cancer resistance protein (BCRP/ABCG2)

Breast cancer resistance protein (BCRP/ABCG2) plays an important role in determining the absorption and disposition of consumed xenobiotics including various drugs and dietary phytochemicals and is also one of the prominent efflux transporters involved in multidrug resistance (MDR). In this study, we have investigated the interactions between ABCG2 and 56 naturally-occurring phytochemicals including phenolic acids, flavonoids, triterpenes and other common dietary phytochemicals, as well as two non plant-based compounds (hippuric acid and propyl gallate) using cell- and membrane-based transport inhibition assays. Of the non-flavonoid phytochemicals tested, berberine, celastrol, ellagic acid, limonin, oleanolic acid, propyl gallate, sinapic acid and ursolic acid demonstrated significant inhibition of ABCG2-mediated transport. Chrysoeriol, laricitrin, myricetin 3′,4′,5′-trimethylether, pinocembrin, quercitrin, tamarixetin, tricetin and tricetin 3′,4′,5′-trimethylether were also identified as novel flavonoid ABCG2 inhibitors. The identified inhibitory activity of dietary phytochemicals on ABCG2 provides a framework for further investigation of ABCG2-modulated phytochemical bioavailability, MDR, and possible food–drug interactions.     

Degradation of ozone-refractory organic phosphates in wastewater by ozone and ozone/hydrogen peroxide (peroxone): the role of ozone consumption by dissolved organic matter

Ozonation is very effective in eliminating micropollutants that react fast with ozone (k > 10(3) M(-1) s(-1)), but there are also ozone-refractory (k < 10 M(-1) s(-1)) micropollutants such as X-ray contrast media, organic phosphates, and others. Yet, they are degraded upon ozonation to some extent, and this is due to (?)OH radicals generated in the reaction of ozone with organic matter in wastewater (DOM, determined as DOC). The elimination of tri-n-butyl phosphate (TnBP) and tris-2-chloroisopropyl phosphate (TCPP), added to wastewater in trace amounts, was studied as a function of the ozone dose and found to follow first-order kinetics. TnBP and TCPP concentrations are halved at ozone to DOC ratios of ～0.25 and ～1.0, respectively. The (?)OH rate constant of TCPP was estimated at (7 ± 2) × 10(8) M(-1) s(-1) by pulse radiolysis. Addition of 1 mg H(2)O(2)/L for increasing the (?)OH yield had very little effect. This is due to the low rate of reaction of H(2)O(2) with ozone at wastewater conditions (pH 8) that competes unfavorably with the reaction of ozone with wastewater DOC. Simulations based on the reported (No?the et al., ES&T 2009, 43, 5990-5995) (?)OH yield (13%) and (?)OH scavenger capacity of wastewater (3.2 × 10(4) (mgC/L)(-1) s(-1)) confirm the experimental data. Based on a typically applied molar ratio of ozone and H(2)O(2) of 2, the contribution of H(2)O(2) addition on the (?)OH yield is shown to become important only at high ozone doses.     

棉与Tactel(R)交织高弹吸湿排汗面料的染整工艺探讨

特达纤维是杜邦公司推出的一种新型高品质聚酰胺纤维,"特达"是其商品注册名称"Tactel(R)"的谐音译名.聚酰胺纤维的品种较多,但其分子主链都是由酰胺键连接起来的,国外同类商品有耐纶、尼龙、卡葡隆等称谓.     

Crystallization kinetics of polymorphic forms of a molecular compound constructed by SOS (1,3-distearoyl-2-oleoyl-sn-glycerol) and SSO (1,2-distearoyl-3-oleoyl-rac-glycerol)

Crystallization kinetics of binary mixture phases of SOS (1,3-distearoyl-2-oleoyl-sn-glycerol) and SSO (1,2-distearoyl-3-oleoyl-rac-glycerol) were examined with time-resolved X-ray diffraction (XRD) and DSC methods. Formation of three polymorphic forms, named _c, β′_c and β_c, of a molecular compound was observed at a SOS/SSO=50/50 concentration ratio. The XRD data showed that all three polymorphs were arranged in a double chain-length structure, although a triple chain-length structure is formed in and β′ forms of SSO, and β′ and β forms of SOS. The time-resolved XRD studies showed that _c and β_c forms of the molecular compound crystallized more rapidly than the corresponding polymorphic forms of SOS and SSO. The results were discussed in terms of molecular chain–chain interactions of SOS and SSO, by assuming that kinetic processes of nucleation may prefer the formation of the _c and β_c forms arranged in the double chain-length structure.     

Mg（OH）_2/硅藻土催化合成2,2,6,6-四甲基哌啶氮氧自由基（TEMPO）

该文采用DOE实验设计方案进行实验,通过Minitab数据分析软件找出影响合成反应的主要因子是反应温度和投料比;然后结合单因素法分析得到合成2,2,6,6-四甲基哌啶氮氧自由基（TEMPO）最适宜的工艺条件为：pH=7.5,双氧水滴加时间为2 h,催化剂用量为0.20 g,反应温度为70℃,H2O2和2,2,6,6-四甲基哌啶（TEMP）的投料比为2.5∶1。在此工艺条件下合成TEMPO的得率为94.15%,产品纯度为100%。     

Candida etchellsii产2(5)-乙基-4-羟基-5(2)-甲基-3(2H)-呋喃酮的影响因素

在埃切假丝酵母(Candida etchellsii)发酵过程中,通过盐度调控和氨基酸添加,强化目标产物HEMF(2(5)-乙基-4-羟基-5(2)-甲基-3(2H)-呋喃酮)的合成效率。分阶段调控发酵体系的盐度(初始阶段控制CaCl浓度为200 g/L,发酵40 h后提升至220 g/L),结合氨基酸添加(向发酵体系中添加丙氨酸、精氨酸和甘氨酸各1.67 g/L)。摇瓶结果表明:酵母C.etchellsii合成HEMF,其产量为110.74 mg/L。7 L发酵罐上罐验证,HEMF产量达到121.51 mg/L,相比空白(200 g/L CaCl浓度下且没有添加氨基酸)提高了21.2倍。分阶段盐度调控结合氨基酸添加策略显著强化了C.etchellsii对HEMF的合成。     

Identification and functional analysis of bull (Bos taurus) cauda epididymal fluid proteome

Despite recent advances in bull epididymal fluid proteome research, significant numbers of proteins secreted to epididymal lumen remain unidentified. The objective of this study was to expand the number of identified cauda epididymal fluid proteins in bulls and to contextualize them in a broader view of their mutual interactions and involvement in biological processes and pathways, to fully elucidate the ways in which epididymal fluid proteins are involved in storage and maturation of spermatozoa in epididymis. We collected postmortem cauda epididymal fluid from 6 mature Holstein Friesian bulls. We performed the identification of proteins using 2-dimensional electrophoresis coupled with MALDI mass spectrometry. Analysis of functionality and pathway involvement of identified proteins was performed using Ingenuity Pathway Analysis software. We identified a total of 189 epididymal fluid proteins, out of which 100 were newly identified in bull epididymal fluid. We have combined our data with 2 previously performed bull epididymal fluid proteome identifications, yielding 280 proteins total, and analyzed it. The main canonical pathways involving epididymal proteins were glycolysis, gluconeogenesis, protein ubiquitination pathway, nuclear factor-erythroid 2-related factor 2-mediated oxidative stress response, and farnesoid X receptor/retinoid X receptor activation. The main biological functions potentially performed by epididymal fluid proteins included carbohydrate metabolism, cellular growth and proliferation, cell death and survival, and small molecule biochemistry. Overall, our results have pointed out multiple novel pathways in bull epididymal fluid that might take part in various aspects of maturation and protection processes of epididymal spermatozoa.     

Pu(V)O2+ adsorption and reduction by synthetic magnetite (Fe3O4)

Changes in aqueous- and solid-phase Pu oxidation state were monitored over time in magnetite (Fe3O4) suspensions containing 239Pu(V)-amended 0.01 M NaCl. Oxidation state distribution was determined by leaching of Pu into an aqueous phase followed by an ultrafiltration/solvent extraction technique. The capability of the technique to measure Pu oxidation state distribution was verified using 230Th(IV), 237Np(V), and 233U(VI) as oxidation state analogues. Reduction of Pu(V) was observed at all pH values (pH 3 to 8) and magnetite concentrations (10 to 100 m2 L(-1)). In the pH range 5 to 8, adsorption was a rate-limiting step, and reduction was mediated by the solid phase; at pH 3 reduction occurred in the aqueous phase. The overall reaction (describing both adsorption and reduction of Pu(V)) was found to be approximately first order with respect to the magnetite concentration and of order -0.34+/-0.02 with respect to the hydrogen ion concentration. Assuming first order dependence with respect to Pu, the overall reaction rate constant was calculated as k(rxn) = 4.79+/-0.62 x 10(-8) (m(-2) L)0.99(mol(-1) L)-0.34(s(-1)). The Pu(IV) solid-phase species became more stable over time.     

Concurrent Separation of CO(2) and H(2)O from Air by a Temperature-Vacuum Swing Adsorption/Desorption Cycle

A temperature-vacuum swing (TVS) cyclic process is applied to an amine-functionalized nanofibrilated cellulose sorbent to concurrently extract CO(2) and water vapor from ambient air. The promoting effect of the relative humidity on the CO(2) capture capacity and on the amount of coadsorbed water is quantified. The measured specific CO(2) capacities range from 0.32 to 0.65 mmol/g, and the corresponding specific H(2)O capacities range from 0.87 to 4.76 mmol/g for adsorption temperatures varying between 10 and 30 °C and relative humidities varying between 20 and 80%. Desorption of CO(2) is achieved at 95 °C and 50 mbar(abs) without dilution by a purge gas, yielding a purity exceeding 94.4%. Sorbent stability and a closed mass balance for both H(2)O and CO(2) are demonstrated for ten consecutive adsorption-desorption cycles. The specific energy requirements of the TVS process based on the measured H(2)O and CO(2) capacities are estimated to be 12.5 kJ/mol(CO2) of mechanical (pumping) work and between 493 and 640 kJ/mol(CO2) of heat at below 100 °C, depending on the air relative humidity. For a targeted CO(2) capacity of 2 mmol/g, the heat requirement would be reduced to between 272 and 530 kJ/mol(CO2), depending strongly on the amount of coadsorbed water.     

The release of lead from the reduction of lead oxide (PbO2) by natural organic matter

PbO2 has been identified as an important scale in some distribution systems that historically use lead service lines and free chlorine for maintaining a disinfectant residual. The stability of this highly insoluble scale with respect to its reductive dissolution may play an important role in lead release into drinking water. In this study, we investigated the release of lead from a commercially available PbO2 in the presence of natural organic matter (NOM) using a hydrophobic acid extracted from the Iowa River. Experiments were conducted using synthetic solutions with different NOM concentrations, solution pH, and NOM samples with different levels of prechlorination. It was found that release of lead from PbO2 occurred both in solutions with and without NOM, and the extent of lead release increased with increasing NOM concentration and decreasing pH value. Furthermore, the released lead was Pb(II) and not particulate PbO2 conclusively showing that reductive dissolution occurred. Prechlorination of NOM reduced the rate of lead release. Our results indicate that PbO2 can be reduced both by water and NOM. Characterization of final solid phases by scanning electron microscopy and X-ray photoelectron spectroscopy are also presented.     

Post-translational modifications in glycosylation status during epididymal passage and significance in fertility of a 33 kDa glycoprotein (MEF3) of rhesus monkey (Macaca mulatta)

The present study reports data on post-translational modifications in the glycosylation status during epididymal passage and significance in fertility of a 33 kDa glycoprotein of rhesus monkey (Macaca mulatta), designated as MEF3 (monkey epididymal fluid protein 3). MEF3 exhibited strong affinity for N-linked alpha-D-mannose groups and O-linked N-Ac-galactosamine linkages in epididymal fluids and exhibited moderate affinity for N-Ac-glucosaminylated (wheat germ agglutinin), fucosylated (Tetragonolotus purpurea), and N-Ac-galactosamine (peanut agglutinin) residues on more mature corpus and caudal spermatozoa in a maturation-dependent manner on Western blots probed with specific biotinylated lectins. Polyclonal antiserum raised against affinity-purified MEF3 from caudal epididymal fluid (CEF) cross-reacted specifically with CEF and caudal sperm membrane of macaque and with Triton X-100 extract of ejaculated human spermatozoa, suggesting the existence of antigenically related components in both species. The tangled agglutination caused by anti-33 kDa serum of human spermatozoa, along with localization of MEF3 on entire sperm surface of epididymal and testicular sperm of monkey and human spermatozoa, suggest the significance of MEF3 in sperm function. The 100% inhibition of fertility of immunized female rabbits with this protein in vivo and inhibition of human sperm penetration in zona-free hamster eggs in vitro suggests the functional significance of MEF3 in fertility. Together, these results clearly indicate that MEF3 has potential significance as a target for antibodies that inhibit sperm function and fertility.     

Atmospheric chemistry of HFE-7500 [n-C3F7CF(OC2H5)CF(CF3)2]: reaction with OH radicals and Cl atoms and atmospheric fate of n-C3F7CF(OCHO*)CF(CF3)2 and n-C3F7CF(OCH2CH2O*)CF(CF3)2 radicals

Relative rate techniques were used to measure k(OH + HFE-7500) = (2.6+/-0.6) x 10(-14), k(Cl + HFE-7500) = (2.3+/-0.7) x 10(-12), k[Cl + n-C3F7CF(OC(O)H)CF(CF3)2] = (9.7+/-1.4) x 10(-15), and k[Cl + n-C3F7CF(OC(O)CH3)CF(CF3)2] < 6 x 10(-17) cm3 molecule(-1) s(-1) at 295 K [HFE-7500 = n-C3F7-CF(OC2H5)CF(CF3)2]. From the value of k(OH + HFE-7500) an estimate of 2.2 years for the atmospheric lifetime of HFE-7500 is obtained. Two competing loss mechanisms for n-C3F7-CF(OCHO.CH3)CF(CF3)2 radicals were identified in 700 Torr of N2/O2 diluent at 295 K; reaction with O2 and decomposition via C-C bond scission with kO2/k(decomp) = 0.013+/-0.006 Torr(-1). The Cl atom initiated oxidation of HFE-7500 in N2/O2 diluent gives n-C3F7CF(OC(O)CH3)CF(CF3)2 as the major product and n-C3F7CF(OC(O)H)CF(CF3)2 as a minor product. The atmospheric oxidation of HFE-7500 gives n-C3F7-CF(OC(O)CH3)CF(CF3)2 and n-C3F7CF(OC(O)H)CF(CF3)2 as oxidation products. The results are discussed with respect to the atmospheric chemistry and environmental impact of HFE-7500.