Unveiling the temperature-dependent thermoelectric properties of the undoped and Na-doped monolayer SnSe allotropes: a comparative study

Motivated by the excellent thermoelectric (TE) performance of bulk SnSe, extensive attention has been drawn to the TE properties of the monolayer SnSe. To uncover the fundamental mechanism of manipulating the TE performance of the SnSe monolayer, we perform a systematic study on the TE properties of five monolayer SnSe allotropes such asα-,β-,γ-,δ-, andε-SnSe based on the density functional theory and the non-equilibrium Green's functions. By comparing the TE properties of the Na-doped SnSe allotropes with the undoped ones, the influences of the Na doping and the temperature on the TE properties are deeply investigated. It is shown that the figure of meritZTwill increase as the temperature increases, which is the same for almost all the Na-doped and undoped cases. The Na doping can enhance or suppress theZTin different SnSe allotropes at different temperatures, implying the presence of the anomalous suppression of theZT. The Na doping inducedZTsuppression may be caused basically by the sharp decrease of the power factor and the weak decrease of the electronic thermal conductance, rather than by the decrease of the phononic thermal conductance. We hope this work will be able to enrich the understanding of the manipulation of TE properties by means of dimensions, structurization, doping, and temperature.

[Effects of immune responses mediated by topological structures of three-dimensional bioprinted scaffolds on hair follicle cycle in mice]

Objective: To explore the effects of the immune responses mediated by topological structures of three-dimensional bioprinted scaffolds on hair follicle cycle in mice. Methods: The study was an experimental research. The alginate-gelatin composite hydrogels were printed into scaffolds using a three-dimensional bioprinter and named T45 scaffolds, T60 scaffolds, and T90 scaffolds according to the 3 topological structures of the scaffolds (the rotation angles of the printhead during printing were 45°, 60°, and 90°, respectively), and the morphology of the three scaffolds was observed after cross-linking by naked eyes. Nine 8-week-old female C57BL/6J mice were divided into T45 group, T60 group, and T90 group, according to the random number table, with three mice in each group, and the T45, T60, and T90 scaffolds were subcutaneously implanted on the back of mice, respectively. On post implantation day (PID) 7, the hair growth in the dorsal depilated area of mice was observed, the thickness of the fiber capsule around the scaffolds was observed by hematoxylin-eosin staining, and the expression levels of CD68, bone morphogenetic protein-2 (BMP-2), and tumor necrosis factor (TNF) protein in the tissue surrounding the scaffolds were observed by immunofluorescence staining. The samples of the above experiments were all 3. Results: The topological structures of the three scaffolds were all clear with high fidelity after cross-linking. On PID 7, the hair growth was obvious in the dorsal depilated area of mice in T45 group and T90 group, while hair growth was slow in the scaffold implantation area of mice in T60 group, which was significantly different from that of the unimplanted area. On PID 7, compared with (18±4) μm in T90 group, the thickness of both the fiber capsule around the scaffolds ((39±4) and (55±8) μm) of mice in T45 group and T60 group was significantly increased (P<0.05); the thickness of the fiber capsule around the scaffolds of mice in T60 group was also significantly increased compared with that in T45 group (P<0.05). On PID 7, the expression level of CD68 protein in the tissue surrounding the scaffolds of mice in T60 group was significantly higher than the levels in T45 group and T90 group (with both P values <0.05). The expression level of BMP-2 protein in the tissue surrounding the scaffolds of mice in T60 group was significantly higher than the levels in T45 group and T90 group (with both P values <0.05), and the expression level of BMP-2 protein in the tissue surrounding the scaffolds of mice in T45 group was significantly higher than that in T90 group (P<0.05). The expression level of TNF protein in the tissue surrounding the scaffolds of mice in T60 group was significantly lower than the levels in T45 group and T90 group (with both P values <0.05). Conclusions: Three-dimensional bioprinted scaffolds with different topological structures mediate different degrees of immune responses after being implanted in mice. A moderate immune response promotes hair growth in depilated area of mice, while an excessive immune response results inhibits the hair follicle entering into the anagen phase.

[Investigation of acute poisoning event caused by carbofuran]

Objective: To analyze the epidemiological characteristics and response process of an acute poisoning event caused by carbofuran in buttered tea and provide scientific evidence for the investigation of similar events in the future. Methods: Field epidemiological survey, animal experiments and laboratory tests were conducted for an acute poisoning event occurred in Suopo township of Danba county of Sichuan province in 2018. Descriptive epidemiological method was used to analyze the epidemiological characteristics of the acute poisoning event. Results: A total of 26 poisoning cases occurred in 3 villages. The total attack rate was 41.27%. No death cases were reported. The 26 cases occurred in a few minutes after drinking buttered tea, the main symptoms were vomit, dizziness, miosis and nausea. A dog showed the same symptoms after drinking a sample of buttered tea. Carbofuran was detected in buttered tea, vomitus and zanba samples. Conclusions: The acute poisoning was caused by carbofuran in buttered tea, the transmission mode was point source spread. Effective epidemiological investigation and simple animal experiment can provide evidence for the rapid sample detection and clinical treatment of cases in emergency response. Timely case treatment and strict poisoning source control are the key measures to reduce casualty and prevent the spread of poisoning.

[The efficacy comparation of adenoidectomy with acupuncture and tympanonstomy in children secretory otitis media]

Objective:This study aims to the comparative study of AT+A (adenoidectomy with acupuncture) and AT+T (adenoidectomy with tympanonstomy tube) to monitor and compare the therapeutic effect and prognosis of secretory otitis media in children. The study make a summary and give the clinical suggestions as well.Method:We collected and analyzed 280 outpatients of children secretory otitis media from March 2015 to March 2016.Among them,172 cases took the adenoidectomy with acupuncture and 108 cases took the adenoidectomy with tympanonstomy tube. This research used the therapeutic effect indicators,middle ear effusion time and one year follow-up to evaluate the pros and cons of two surgery methods in different areas.Result:The patients of both groups had relatively good therapeutic effect which promoted with time. There were no significant difference between AT+A and AT+T in tympanic membrane. While AT+T group acted better than AT+A group in pure tone average and tympanum figure. The middle ear effusion time of AT+T group was significantly shorter than AT+A group. In one year follow-up, there were no difference in hearing loss between two groups.But AT+T group performed better in recurrence rate, infection rate and total rate.Conclusion:Since the adenoidectomy with tympanonstomy tube method has a lot of advantages over adenoidectomy with acupuncture,it's better to use AT+T in severechildren secretory otitis media when situation is available.

Kaempferol inhibited VEGF and PGF expression and in vitro angiogenesis of HRECs under diabetic-like environment

Diabetic retinopathy (DR) is one of the common and specific microvascular complications of diabetes. This study aimed to investigate the anti-angiogenic effect of kaempferol and explore its underlying molecular mechanisms. The mRNA expression level of vascular endothelial growth factor (VEGF) and placenta growth factor (PGF) and the concentrations of secreted VEGF and PGF were measured by qTR-PCR and ELISA assay, respectively. Human retinal endothelial cells (HRECs) proliferation, migration, and sprouting were measured by CCK-8 and transwell, scratching wound, and tube formation assays, respectively. Protein levels were determined by western blot. High glucose (25 mM) increased the mRNA expression levels of VEGF and PGF as well as the concentrations of secreted VEGF and PGF in HRECs, which can be antagonized by kaempferol (25 µM). Kaempferol (5-25 µM) significantly suppressed cell proliferation, migration, migration distance and sprouting of HRECs under high glucose condition. The anti-angiogenic effect of kaempferol was mediated via downregulating the expression of PI3K and inhibiting the activation of Erk1/2, Src, and Akt1. This study indicates that kaempferol suppressed angiogenesis of HRECs via targeting VEGF and PGF to inhibit the activation of Src-Akt1-Erk1/2 signaling pathway. The results suggest that kaempferol may be a potential drug for better management of DR.

[Effectiveness of bupropion and counseling for smoking cessation]

OBJECTIVE

To evaluate the effectiveness of bupropion for smoking cessation among Chinese smokers at a smoking cessation clinic.

METHODS

A prospective observational study was conducted in a hospital located in Beijing during 2008 and from 28 to 31 October 2014. A total of 287 smokers (265 men and 22 women) were assessed using data from structured questionnaires at baseline and were followed up at 1 and 6 months. Trained physician counselors provided free brief education and individual counseling sessions for all participants at the first visit. A total 131 participants were prescribed bupropion in addition to counseling. The counseling plus bupropion group was compared with the group who underwent counseling without bupropion. Outcomes were self-reported 7-day point prevalence abstinence rates at 1- and 6-month follow-up and continuous abstinence rates at 6-month follow-up. Smoking reduction rates at 1 and 6 months were also measured.

RESULTS

By intention-to-treat analysis, the 7-day point prevalence abstinence rate of the bupropion group at 1 and 6 months was higher than for the counseling-only group: at 1-month follow-up, 26.0% (34/131) vs. 15.4% (24/156), with OR (95% CI) 1.93(1.07-3.46); these rates at 6-month follow-up were 27.8% (35/131) vs. 15.4% (24/156), with OR (95% CI) 2.01(1.12-3.59). The 1-month continuous abstinence rate at 6 months was higher in the bupropion group: 26.0% (34/131) vs. 14.7% (23/156), with OR (95%CI) 2.03(1.12-3.66). Participants in the bupropion group also had a higher smoking reduction rate at 1 month than those in the counseling-only group: 55.0% (72/131) vs. 38.5% (60/156), with OR (95%CI) 1.95 (1.22-3.13).

CONCLUSION

Prescription of bupropion at this smoking cessation clinic was effective in doubling the quitting rates and smoking reduction rates among Chinese smokers.

Single nucleotide polymorphisms predisposing to asthma in children of Mauritian Indian and Chinese Han ethnicity

Our objective was to investigate the distributions of six single nucleotide polymorphisms (SNPs) MS4A2 E237G, MS4A2 C-109T, ADRB2 R16G, IL4RA I75V, IL4 C-590T, and IL13 C1923T in Mauritian Indian and Chinese Han children with asthma. This case-control association study enrolled 382 unrelated Mauritian Indian children, 193 with asthma and 189 healthy controls, and 384 unrelated Chinese Han children, 192 with asthma and 192 healthy controls. The SNP loci were genotyped using polymerase chain reaction (PCR)-restriction fragment length polymorphism for the Chinese Han samples and TaqMan real-time quantitative PCR for the Mauritian Indian samples. In the Mauritian Indian children, there was a significant difference in the distribution of IL13 C1923T between the asthma and control groups (P=0.033). The frequency of IL13 C1923T T/T in the Mauritian Indian asthma group was significantly higher than in the control group [odds ratio (OR)=2.119, 95% confidence interval=1.048-4.285]. The Chinese Han children with asthma had significantly higher frequencies of MS4A2 C-109T T/T (OR=1.961, P=0.001) and ADRB2 R16G A/A (OR=2.575, P=0.000) than the control group. The IL13 C1923T locus predisposed to asthma in Mauritian Indian children, which represents an ethnic difference from the Chinese Han population. The MS4A2 C-109T T/T and ADRB2 R16G A/A genotypes were associated with asthma in the Chinese Han children.

Strain dynamics of ultrathin VO₂ film grown on TiO₂ (001) and the associated phase transition modulation

Tuning the metal insulator transition (MIT) behavior of VO2 film through the interfacial strain is effective for practical applications. However, the mechanism for strain-modulated MIT is still under debate. Here we directly record the strain dynamics of ultrathin VO2 film on TiO2 substrate and reveal the intrinsic modulation process by means of synchrotron radiation and first-principles calculations. It is observed that the MIT process of the obtained VO2 films can be modulated continuously via the interfacial strain. The relationship between the phase transition temperature and the strain evolution is established from the initial film growth. From the interfacial strain dynamics and theoretical calculations, we claim that the electronic orbital occupancy is strongly affected by the interfacial strain, which changes also the electron-electron correlation and controls the phase transition temperature. These findings open the possibility of an active tuning of phase transition for the thin VO2 film through the interfacial lattice engineering.

Characteristics of Lactobacillus parafarraginis ZH1 and its role in improving the aerobic stability of silages

AIMS

Lactobacillus parafarraginis ZH1 isolated from silage was characterized, and the effects of inoculating ZH1 and Lact. buchneri (LB) on the aerobic stability of sweet corn stalk (SCS) silage and whole-plant oat (WPO) silage ensiled at 15 and 30°C were studied.

METHODS AND RESULTS

After ensiling of SCS or WPO in plastic bottle silo for 45 days, silos were opened, and aerobic stability was studied by monitoring temperature change with thermo recorders in silage for 6 days. SCS silage and WPO silage were well conserved naturally at both storage temperatures. However, silages were prone to aerobic deterioration due to the presence of residual yeasts. ZH1 inoculated silages ensiled at both temperatures, LB inoculated silages ensiled at 30°C had better aerobic stability than the uninoculated silages and the LB-inoculated silage at 15°C.

CONCLUSIONS

Strain ZH1 improved the aerobic stability of SCS silage and WPO silage ensiled at both 15 and 30°C, while LB improved the aerobic stability of silage only ensiled at the high temperature of 30°C.

SIGNIFICANCE AND IMPACT OF THE STUDY

The new strain ZH1 can be used as an effective inhibitor for aerobic deterioration of silage maintained from 15 to 30°C.

Osteogenesis induced in goat bone marrow progenitor cells by recombinant adenovirus coexpressing bone morphogenetic protein 2 and basic fibroblast growth factor

Bone morphogenetic protein 2 (BMP2) and basic fibroblast growth factor (bFGF) have been shown to exhibit a synergistic effect to promote bone repair and healing. In this study, we constructed a novel adenovirus with high coexpression of BMP2 and bFGF and evaluated its effect on osteogenic differentiation of goat bone marrow progenitor cells (BMPCs). Recombinant adenovirus Ad-BMP2-bFGF was constructed by using the T2A sequence. BMPCs were isolated from goats by density gradient centrifugation and adherent cell culture, and were then infected with Ad-BMP2-bFGF or Ad-BMP2. Expression of BMP2 and bFGF was detected by ELISA, and alkaline phosphatase (ALP) activity was detected by an ALP assay kit. In addition, von Kossa staining and immunocytochemical staining of collagen II were performed on BMPCs 21 days after infection. There was a high coexpression of BMP2 and bFGF in BMPCs infected with Ad-BMP2-bFGF. Twenty-one days after infection, ALP activity was significantly higher in BMPCs infected with Ad-BMP2-bFGF than in those infected with Ad-BMP2. Larger and more mineralized calcium nodules, as well as stronger collagen II staining, were observed in BMPCs infected with Ad-BMP2-bFGF than in those infected with Ad-BMP2. In summary, we developed a novel adenovirus vector Ad-BMP2-bFGF for simultaneous high coexpression of BMP2 and bFGF, which could induce BMPCs to differentiate efficiently into osteoblasts.

Germline-specific and sexually dimorphic expression of a dead end gene homologue in turbot (Scophthalmus maximus)

Germ cells are indispensable for gonadal development and fertility. However, the physiological mechanisms regulating germ cell development in marine fish are poorly understood due to a lack of germ cell markers. The dead end (dnd) gene is a vertebrate-specific component of germplasm crucial for primordial germ cells (PGCs) migration and development in teleosts. In this study, we identified a dnd homologue (Smdnd) in turbot (Scophthalmus maximus) and investigated its expression pattern during embryogenesis and gonadal development. The deduced amino acid sequence of Smdnd shared several conserved motifs of Dnd homologues as well as high identity to other Dnd proteins. Phylogenetic analysis revealed that the SmDnd was closely related to its teleost counterparts. Reverse transcription polymerase chain reaction (RT-PCR) and in situ hybridization revealed that Smdnd transcripts could be exclusively detected in germ cells, including presumptive PGC and adult male and female germ cells. In addition, an interesting sexually dimorphic expression of Smdnd during gonadal development was observed by real-time PCR. Female turbot showed greater (P < 0.05) Smdnd expression than male before sex maturation. This difference reduced gradually due to the upregulation of Smdnd in the male during the period corresponding to spermatogonia proliferation and meiosis. These results indicate that Smdnd can be used as a germ cell marker in turbot. In addition, the temporal and sex differences in Smdnd expression indicate that this gene may play different roles in gonadal development in both sexes.

Characteristics of lactic acid bacteria isolates and their inoculating effects on the silage fermentation at high temperature

Thermotolerant strains of lactic acid bacteria (LAB) were screened for their suitability for silage making at high temperatures. Four selected strains were identified by 16S rRNA sequencing analyses and added to unwilted and wilted Italian ryegrass for ensiling at 45°C. All four strains (HT1, HT2, HT3 and HT4) grew at 50°C and pH 4·0. Strains HT1 and HT2 were identified as Lactobacillus rhamnosus; HT3 and HT4 were identified as Lact. fermentum. Strains HT1 and HT2 were the most effective at improving the fermentation quality of Italian ryegrass silage, irrespective of wilting, as indicated by lower pH values, less NH(3) -N, and more lactic acid. In contrast, strains HT3, HT4 and a commercial inoculant consisting of Lact. plantarum and Pediococcus acidilactici conferred no or reduced benefits. Wilting alone did not improve the fermentation quality of Italian ryegrass at 45°C. Inoculating with thermotolerant Lact. rhamnosus HT1 and HT2 could improve the fermentation quality of silage at high temperatures. Lactobacillus rhamnosus HT1 and HT2 can be used as inoculants for silage making in the tropics and subtropics and could play an important role in developing silage production in such regions.

SIGNIFICANCE AND IMPACT OF THE STUDY

Grasses are often difficult to ensile in the tropics and subtropics because of the high temperatures there. To solve this problem, we screened for thermotolerant lactic acid bacteria and obtained two valuable strains of Lactobacillus rhamnosus, HT1 and HT2, which proved to be beneficial to silage fermentation at high temperatures. Lactobacillus rhamnosus HT1 and HT2 can be used as inoculants for silage making in the tropics and subtropics, and will play an important role in developing silage production in such regions.

VP90 of white spot syndrome virus interacts with VP26 and VP28

Identification of structural protein relationships is likely to be important for virus assembly and anti-WSSV strategies. In this paper, VP90 of white spot syndrome virus (WSSV) was characterized. Temporal-transcription analysis showed that VP90 is expressed in the late stage of WSSV infection. Far-western and matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) assay showed that VP90 interacts with VP26 and VP28, two major envelope proteins. Far-western blot with recombinant VP26 (rVP26), N-terminal end of VP28 (rVP28N) and C-terminal end of VP28 (rVP28C) provided further evidence for interaction of rVP90 and rVP26 or rVP28. These results suggest that VP90 is anchored to the envelope through interacting with VP26 and VP28.

Digestive enzyme activities of turbot (Scophthalmus maximus L.) during early developmental stages under culture condition

Digestive enzyme activities were analysed in turbot (Scophthalmus maximus) from hatching until 60 days after hatching (DAH). Trypsin sharply increased to the climax at 17 DAH and decreased until 31 DAH followed by a stable level thereafter. Amylase was determined at 4 DAH, reached the maximum value at 19 DAH and declined sharply to 39 DAH and remained at a low level thereafter, suggesting the carbohydrate component should remain at a low level in formulated diets. Pepsin was detected at 9 DAH and increased to 34 DAH and then remained at a stable level. The above results revealed pancreatic enzymes are no longer main enzymes for food digestion after the formation of functional stomach. Leucine-alanine peptidase (Leu-ala) and alkaline phosphatase (AP) and leucine aminopeptidase N (LAP) were found in newly hatched larvae. Both AP and LAP activities markedly increased to 23 DAH, decreased abruptly to 50 DAH and increased gradually to 60 DAH. Leu-ala reached the plateau from 23 to 39 DAH, followed by a decline to 46 DAH and an increase until 60 DAH. The brush border membrane (BBM)-bound enzyme activities increased from 30% at 31 DAH to 81% at 38 DAH of the total activities, indicating the maturation of intestinal tract.

Skeletal development and abnormalities of the vertebral column and of the fins in hatchery-reared turbot Scophthalmus maximus

To describe the skeletal development and abnormalities in turbot Scophthalmus maximus, samples were collected every day from hatching to 60 days after hatching (DAH). A whole-mount cartilage and bone-staining technique was used. Vertebral ontogeny started with the formation of anterior haemal arches at 5·1 mm standard length (L(S) ) c. 11 DAH, and was completed by the full attainment of parapophyses at 16·9 mm L(S) c. 31 DAH. Vertebral centra started to develop at 6·3 mm L(S) c. 16 DAH and ossification in all centra was visible at 11·0 mm L(S) c. 25 DAH. The caudal fin appeared at 5·1 mm L(S) c. 11 DAH and ossification was visible at 20·6 mm L(S) c. 37 DAH. The onset of dorsal and anal fin elements appeared at 5·8 mm L(S) c. 15 DAH and 6·3 mm L(S) c. 16 DAH, respectively. Ossifications of both dorsal fin and anal fin were visible at 20·6 mm L(S) c. 37 DAH. The pectorals were the only fins present before first feeding, their ossifications were completed at 23·5 mm L(S) c. 48 DAH. Pelvic fins began forming at 7·2 mm L(S) c. 19 DAH and calcification of the whole structure was visible at 19·8 mm L(S) c. 36 DAH. In the present study, 24 types of skeletal abnormalities were observed. About 51% of individuals presented skeletal abnormalities, and the highest occurrence was found in the haemal region of the vertebral column. As for each developmental stage, the most common abnormalities were in the dorsal fin during early metamorphic period (stage 2), vertebral fusion during climax metamorphosis (stage 3) and caudal fin abnormality during both late-metamorphic period (stage 4) and post-metamorphic period (stage 5). Such research will be useful for early detection of skeletal malformations during different growth periods of reared S. maximus.

Germ cells and fertilization differences among Japanese flounder Paralichthys olivaceus, summer flounder Paralichthys dentatus and their first and second generations

The morphology of gametes and the fertilization biology of Japanese flounder Paralichthys olivaceus (Po), summer flounder Paralichthys dentatus (Pd) and their hybrids were examined. Multiple generations (two hybrids: Po♀× Pd♂ (F1) and Pd♀× Po♂; two backcrosses: F1♀× Po♂ and F1♀× Pd♂) were obtained by artificial insemination. Comparison of egg ultrastructure among Po, Pd and F1 showed the morphology of micropyle region and the distribution density of pores were species specific. There were c. 100-200 accessory openings around the micropyle in Po, but not in Pd and F1. The zona radiata thickness and number of parallel bands were similar between F1 and Po, which were different from Pd. Comparison of spermatozoa ultrastructure revealed a close relationship between Po and Pd. Cytologically, the six crosses obeyed normal fertilization and cleavage processes, and only one male pronucleus was observed in a fertilized egg, indicating a monospermic fertilization pattern. Analysis of the time distribution from fertilization to first cleavage revealed an obvious delay at pronucleus fusion in the Pd × Po cross. The delay might indicate some cytoplasmic-nuclear incompatibility during the process of fertilization.

Study on permeability of DMSO in embryos of red seabream (Pagrus major) by capillary electrophoresis

The objectives were to investigate the permeability of DMSO to red seabream (Pagrus major) embryos by capillary electrophoresis and the effects of DMSO concentrations (5 to 40 percent, volume basis) and immersion times (10, 30 and 60 min) on hatching rate and morphology. The results suggested the internal DMSO concentrations were positively related with the external concentrations and exposure times, while the hatching rate was negatively related. The hatching rate decreased drastically (less than 50 percent) after exposure in 35 percent, 20 percent and 15 percent DMSO for over 10, 30 and 60 min, respectively. In all groups, when hatching rate was greater 50 percent, the internal DMSO concentration was less than 2 percent, which was still insufficient for successful cryopreservation. Morphological changes indicated the chorion was permeable to the cryoprotectant. A sign of dehydration in yolk were observed, for a significant decrease in the maximal yolk sac diameter. However, further research was needed to investigate whether the DMSO permeated into the yolk.

Bilateral Bispectral Index (BIS)-Vista as a measure of physiologic sleep in sleep-deprived anesthesiologists

BACKGROUND

Anesthesiologists who work extended hours exhibit acute and chronic sleep deprivation. The newest bilateral Bispectral Index (BIS)-Vista monitor offers new advantages over earlier models, which include a new algorithm (version 1.4). One possible useful application for BIS monitoring of physiological sleep would be in critically ill patients who almost uniformly suffer from sleep disruption and deprivation because they loose their circadian rhythm due to the harsh noisy environment of critical care units. Previous studies, which used earlier versions of the BIS monitor to depict normal physiologic sleep, produced widely conflicting results. The aim of our study was to assess whether the new BIS-Vista monitor would exhibit a temporal decline that corresponds to natural physiologic sleep stages in healthy sleep-deprived, post-call anesthesiologists.

METHODS

BIS-Vista sensors were bilaterally mounted, according to the manufacturer guidelines, onto the forehead of 10 healthy sleep-deprived volunteer anesthesiologists. Using the conventional Rechtschaffen and Kales criteria, BIS values during the awake, S1, S2, S3, S4, and rapid eye movement (REM) sleep stages were recorded.

RESULTS

Mean±SD BIS values during the awake, S1, S2, S3, S4, and REM sleep stages significantly declined for the left (96±2, 82±11, 73±10, 53±13, 43±11, 66±9) and right (97±2, 78±11, 69±9, 50±10, 39±13, 61±14) hemispheres respectively. There were no significant interhemispheric differences in BIS values over time (two-way ANOVA). However, in one subject, the left and right BIS values were mostly discordant throughout the recordings.

CONCLUSION

We demonstrated that although the BIS-Vista monitor was neither designed nor validated for monitoring normal physiologic sleep, it depicted a temporal decline that corresponds to normal physiologic sleep stages in sleep-deprived anesthesiologists.

Changes in RNA, DNA, protein contents and growth of turbot Scophthalmus maximus larvae and juveniles

The growth potential of turbot Scophthalmus maximus larvae and juveniles was studied using nucleic acid-based indices and protein variables. The experiment was carried out from 4 to 60 days post hatching (dph). A significant increase in instantaneous growth rate during metamorphosis and retarded growth rate during post-metamorphic phase were observed. Ontogenetic patterns of DNA, RNA and protein all showed developmental stage-specific traits. The RNA:DNA ratio decreased up to 12 dph, then increased rapidly till 19 dph and fluctuated until 35 dph followed by a decline to the end. The RNA:DNA ratio was positively correlated with growth rate of juveniles during the post-metamorphic phase, whereas this ratio was not a sensitive indicator of growth during the pre-metamorphic phase and metamorphosis. The protein:DNA ratio showed a similar tendency to the RNA:DNA ratio. Changes of DNA content and protein:DNA ratio revealed that growth of S. maximus performed mainly by hyperplasia from 4 to 12 dph and hypertrophy until 21 dph during the pre-metamorphic larval phase. Growth was dominantly hypertrophical from the early- to mid-metamorphosing phase and hyperplastic thereafter. The results show that the DNA content and protein:DNA ratio can evaluate growth rates of larval and juvenile S. maximus on a cellular level.

Removal effect of Cr (VI) by adsorbent made from sewage sludge

Adsorbent made from sewage sludge is used to remove the Cr (VI) in wastewater. In this paper, the adsorption capacity, adsorption mechanism and regeneration of the adsorbent are studied. A systematic research is carried out to investigate the influence of adsorption capacities in various conditions, such as contact time, pH and initial dosage of adsorbent. The results show that: the equilibrium time is 6 h; the optimal pH is 2.5. The adsorption capacity increases as the initial concentration increase and as the dosage of activated carbon decrease. The data of adsorption capacity are more fit in Langmuir isotherms. The adsorption follows a pseudo-second-order kinetic model perfectly. From this research, the adsorption rate controlling step is film diffusion when the Cr (VI) concentration is low; otherwise, the adsorption rate controlling step is the diffusion among particles. The results of regeneration of saturated adsorbent show that the saturated adsorbent can be perfectly regenerated using alkali treatment. The regeneration ratio of the saturated adsorbent can reach more than 90% with proper concentration of alkali.

Lectins but not antifungal proteins exhibit anti-nematode activity

A variety of lectins and antifungal proteins were tested for toxicity against the plant parasitic nematodes Ditylenchus dipsaci and Heterodera glycines. It was found that lectins from the mushrooms Xylaria hypoxylon, Agrocybe cylindracea and Tricholoma mongolicum (TML-1) were the most potent against D. dipsaci, with EC(50) being 4.7, 9, and 20mg/ml, respectively. Lectins from Pseudostellaria heterophylla, samta tomato, and the mushrooms T. mongolicum (TML-2), Ganoderma lucidum, and Boletus edulis, and antifungal proteins from Ginkgo biloba toward D. dipsaci and pumpkin Cucurbita moschata had much lower anti-nematode potencies and could be considered as inactive for practical purposes. All lectins except that from P.heterophylle were potent against H.glycines.

An efficient MR image reconstruction method for arbitrary K-space trajectories without density compensation

Non-Cartesian sampling is widely used for fast magnetic resonance imaging (MRI). The well known gridding method usually requires density compensation to adjust the non-uniform sampling density, which is a major source of reconstruction error. Minimum-norm least square (MNLS) reconstruction, on the other hand, does not need density compensation, but requires intensive computations. In this paper, a new version of MNLS reconstruction method is developed using maximum likelihood and is speeded up by incorporating novel non-uniform fast Fourier transform (NUFFT) and bi-conjugate gradient fast Fourier transform (BCG-FFT) techniques. Studies on computer-simulated phantoms and a physically scanned phantom show improved reconstruction accuracy and signal-to-noise ratio compared to gridding method. The method is shown applicable to arbitrary k-space trajectory. Furthermore, we find that the method in fact performs un-blurring in the image space as an equivalent of density compensation in the k-space. Equalizing MNLS solution with gridding algorithm leads to new approaches of finding optimal density compensation functions (DCF). The method has been applied to radially encoded cardiac imaging on small animals. Reconstructed dynamic images of an in vivo mouse heart are shown.

Regional patterns of soil organic carbon stocks in China

Soil organic carbon (SOC) is of great importance in the global carbon cycle. Distribution patterns of SOC in various regions of China constitute a nation-wide baseline for studies on soil carbon changes. This paper presents an integrated and multi-level study on SOC stock patterns of China, and presents baseline SOC stock estimates by great administrative regions, river watersheds, soil type regions and ecosystem. The assignment is done by means of a recently completed 1: 1,000,000 scale soil database of China, which is the most detailed and reliable one in China at the present time. SOC densities of 7292 soil profiles collected across China in the middle of the 1980s were calculated and then linked to corresponding polygons in a digital soil map, resulting in a SOC Density Map of China on a 1: 1,000,000 scale, and a 1 km x 1 km grid map. Corresponding maps of administrative regions, river watersheds, soil types (ST), and ecosystems in China were also prepared with an identical resolution and coordinate control points, allowing GIS analyses. Results show that soils in China cover an area of 9.281 x 10(6)km(2) in total, with a total SOC stock of 89.14 Pg (1 Pg=10(15)g) and a mean SOC density of 96.0 t C/ha. Confidence limits of the SOC stock and density in China are estimated as [89.23 Pg, 89.08 Pg] and [96.143 t C/ha, 95.981 t C/ha] at 95% probability, respectively. The largest total SOC stock (23.60 Pg) is found in South-west China while the highest mean SOC density (181.9 t C/ha) is found in north-east China. The total SOC stock and the mean SOC density in the Yangtze river watershed are 21.05 Pg and 120.0 t C/ha, respectively, while the corresponding figures in the Yellow river watershed are 8.46 Pg and 104.3 t C/ha, respectively. The highest total SOC stocks are found in Inceptisols (34.39 Pg) with SOC density of 102.8 t C/ha. The lowest and highest mean SOC densities are found on Entisols (28.1 t C/ha), and on Histosols (994.728.1 t C/ha), respectively. Finally, the total SOC stock in shrub and forest ecosystem classes are 25.55 and 21.50 Pg, respectively; the highest mean SOC density (209.9 t C/ha) was recorded in the wetland ecosystem class and the lowest (29.0 t C/ha) in the desert ecosystem class. Among five forest ecosystem types, Evergreen conifer forest stores the highest SOC stock (6.81 Pg), and Deciduous conifer forest shows the highest SOC density (225.9 t C/ha). Figures of SOC stocks stratified by Administrative regions, river watersheds, soil types and ecosystem types presented in the study may constitute national-wide baseline for studies of SOC stock changes in various regions in the future.

An alkaline protease from fresh fruiting bodies of the edible mushroom Pleurotus citrinopileatus

A protease was purified from fresh fruiting bodies of the edible mushroom Pleurotus citrinopileatus. The isolation procedure included ion exchange chromatography on DEAE-cellulose, CM-cellulose, and Q-Sepharose and fast protein liquid chromatography-gel filtration on Superdex 75. The protease was unadsorbed on DEAE-cellulose and Q-Sepharose, but adsorbed on CM-cellulose. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the protease demonstrated a single band with a molecular mass of 28 kDa. The protease showed an optimal pH at 10 and an optimal temperature at 50 degrees C. The activity of the protease was not affected by EDTA, indicating that it is not a metalloprotease. The protease exhibited a higher activity in the presence of K(+) and Li(+), but its activity was potently inhibited by Al(3+), Cu(2+), and Hg(2+) ions. It manifested a K (m) of 3.44 mg/ml and a V (max) of 0.139 mg ml(-1) min(-1). It was devoid of ribonuclease and antifungal activities.

Flow cytometry and ultrastructure of cryopreserved red seabream (Pagrus major) sperm

The objectives were to assess motility, fertilizing capacity, structural integrity, and mitochondrial function in fresh versus frozen-thawed (15% DMSO was used as a cryoprotectant) sperm from red seabream (Pagrus major). Mean (+/-S.D.) rates of motility, fertilization and hatching of frozen-thawed sperm were 81.0+/-5.4, 92.8+/-1.9, and 91.8+/-5.2%, respectively; for fresh sperm, they were 87.5+/-7.7, 95.8+/-2.4, and 93.8+/-4.2%. Although motility was lower in frozen-thawed versus fresh sperm (P<0.05), there was no effect (P>0.05) of cryopreservation on fertilization or hatching. Based on scanning and transmission electron microscopy, 77.8+/-5.6% of fresh sperm had normal morphology, whereas for frozen-thawed sperm, 63.0+/-7.2% had normal morphology, 20.6+/-3.1% were slightly damaged (e.g. swelling or rupture of head, mid-piece and tail region as well as mitochondria), and 16.4+/-4.2% were severely damaged. Sperm were stained with propidium iodide and Rhodamine 123 to assess plasma membrane integrity and mitochondrial function, respectively, and examined with flow cytometry. For fresh sperm, 83.9% had an intact membrane and functional mitochondria, whereas for frozen-thawed sperm, 74.8% had an intact membrane and functional mitochondria, 12.7% had a damaged membrane, 9.9% had nonfunctional mitochondria, and 2.6% had both a damaged membrane and nonfunctional mitochondria. In conclusion, ultrastructure and flow cytometry were valuable for assessment of frozen-thawed sperm quality; cryopreservation damaged the sperm but fertilizing ability was not significantly decreased.

Fluids in porous media. I. A hard sponge model

The morphology of many porous materials is spongelike. Despite the abundance of such materials, simple models which allow for a theoretical description of these materials are still lacking. Here, we propose a hard sponge model which is made by digging spherical cavities in a solid continuum. We found an analytical expression for describing the interaction potential between fluid particles and the spongelike porous matrix. The diagrammatic expansions of different correlation functions are derived as well as that of grand potential. We derived also the Ornstein-Zernike (OZ) equations for this model. In contrast to Madden-Glandt model of random porous media [W. G. Madden and E. D. Glandt, J. Stat. Phys. 51, 537 (1988)], the OZ equations for a fluid confined in our hard sponge model have some similarity to the OZ equations of a three-component fluid mixture. We show also how the replica method can be extended to study our sponge model and that the same OZ equations can be derived also from the extended replica method.

Isolation and characterization of a novel lectin from the mushroom Armillaria luteo-virens

From the dried fruiting bodies of the mushroom Armillaria luteo-virens, a dimeric lectin with a molecular mass of 29.4 kDa has been isolated. The purification procedure involved (NH(4))(2)SO(4) precipitation, ion exchange chromatography on DEAE-cellulose, CM-cellulose, and Q-Sepharose, and gel filtration by fast protein liquid chromatography on Superdex 75. The hemagglutinating activity of the lectin could not be inhibited by simple sugars but was inhibited by the polysaccharide inulin. The activity was stable up to 70 degrees C but was acid- and alkali-labile. Salts including FeCl(3), AlCl(3), and ZnCl(2) inhibited the activity whereas MgCl(2), MnCl(2), and CaCl(2) did not. The lectin stimulated mitogenic response of mouse splenocytes with the maximal response achieved by 1microM lectin. Proliferation of tumor cells including MBL2 cells, HeLa cells, and L1210 cells was inhibited by the lectin with an IC(50) of 2.5, 5, and 10 microM, respectively. However, proliferation of HepG2 cells was not affected. The novel aspects of the isolated lectin include a novel N-terminal sequence, fair thermostability, acid stability, and alkali stability, together with potent mitogenic activity toward spleen cells and antiproliferative activity toward tumor cells.

Isarfelin, a peptide with antifungal and insecticidal activities from Isaria felina

Isarfelin, a peptide with inhibitory activity on mycelial growth in Rhizoctonia solani and Sclerotinia sclerotiorum and insecticidal activity toward Leucania separata, was isolated from the mycelia of Isaria felina. The IC50 value of its antifungal activity against R. solani was 3.1 microg mL(-1). However, it was devoid of activity toward several bacterial species including Bacillus subtilis, E. coli and Staphylococcus aureus. The isolation procedure involved ethanol extraction, adsorption on YPR II macropore adsorption resin, ethyl acetate extraction, petroleum ether precipitation and recrystallization from ethyl acetate.

A novel homodimeric lactose-binding lectin from the edible split gill medicinal mushroom Schizophyllum commune

A homodimeric lactose-binding lectin with a molecular mass of 64kDa was isolated from fresh fruiting bodies of the split gill mushroom Schizophyllum commune. The N-terminal sequence of the lectin is similar to a part of the sequence of the cell division protein from Gleobacter violaceus. The lectin was isolated by using a procedure which involved ion exchange chromatography on DEAE-cellulose, CM-cellulose, and Q-Sepharose, and gel filtration by fast protein liquid chromatography on Superdex 75. The hemagglutinating activity of the lectin was stable at temperatures up to 40 degrees C, and in concentrations of NaOH and HCl solution up to 125 and 25mM, respectively. The lectin exhibited potent mitogenic activity toward mouse splenocytes, antiproliferative activity toward tumor cell lines, and inhibitory activity toward HIV-1 reverse transcriptase. It was devoid of antifungal activity.

Dietary methionine requirement of the Chinese egg-laying duck

1. The dietary methionine requirement of egg-laying ducks was assessed by feeding diets supplemented with graded levels of DL-methionine (0, 4, 8, 12, 16 g/kg dietary protein) for 8 weeks. The basal diet contained 175 g protein and 2.6 g methionine per kg feed (or 14.9 g/kg protein) and an estimated ME of 11.5 MJ/kg. 2. A total of 800 Shaoxin laying ducks (420 d old) were randomly divided into 5 groups of 160 each and fed in 4 separate pens. 3. Dietary supplementation of methionine significantly increased egg production and feed conversion efficiency. 4. Dietary methionine requirement for optimum egg production was estimated to be 25.7 g/kg of dietary protein or 4.5 g/kg of the diet or 380 mg/bird-d. 5. Methionine supplementation increased the methionine level in plasma, and the free glutamic acid and aspartic acid concentrations in plasma were quadratically related to dietary methionine levels. Increasing dietary methionine had little effect on egg quality characteristics.

Differential requirement for SLP-76 domains in T cell development and function

The hematopoietic cell-specific adaptor protein, SLP-76, is critical for T cell development and mature T cell receptor (TCR) signaling; however, the structural requirements of SLP-76 for mediating thymopoiesis and mature T cell function remain largely unknown. In this study, transgenic mice were generated to examine the requirements for specific domains of SLP-76 in thymocytes and peripheral T cells in vivo. Examination of mice expressing various mutants of SLP-76 on the null background demonstrates a differential requirement for specific domains of SLP-76 in thymocytes and T cells and provides new insight into the molecular mechanisms underlying SLP-76 function.

HIV-1 gp120 and chemokine activation of Pyk2 and mitogen-activated protein kinases in primary macrophages mediated by calcium-dependent, pertussis toxin-insensitive chemokine receptor signaling

Human immunodeficiency virus type 1 (HIV-1) uses the chemokine receptors CCR5 and CXCR4 as coreceptors for entry. It was recently demonstrated that HIV-1 glycoprotein 120 (gp120) elevated calcium and activated several ionic signaling responses in primary human macrophages, which are important targets for HIV-1 in vivo. This study shows that chemokine receptor engagement by both CCR5-dependent (R5) and CXCR4-dependent (X4) gp120 led to rapid phosphorylation of the focal adhesion-related tyrosine kinase Pyk2 in macrophages. Pyk2 phosphorylation was also induced by macrophage inflammatory protein-1beta (MIP-1beta) and stromal cell-derived factor-1alpha, chemokine ligands for CCR5 and CXCR4. Activation was blocked by EGTA and by a potent blocker of calcium release-activated Ca++ (CRAC) channels, but was insensitive to pertussis toxin (PTX), implicating CRAC-mediated extracellular Ca++ influx but not Galpha(i) protein-dependent mechanisms. Coreceptor engagement by gp120 and chemokines also activated 2 members of the mitogen-activated protein kinase (MAPK) superfamily, c-Jun amino-terminal kinase/stress-activated protein kinase and p38 MAPK. Furthermore, gp120-stimulated macrophages secreted the chemokines monocyte chemotactic protein-1 and MIP-1beta in a manner that was dependent on MAPK activation. Thus, the gp120 signaling cascade in macrophages includes coreceptor binding, PTX-insensitive signal transduction, ionic signaling including Ca++ influx, and activation of Pyk2 and MAPK pathways, and leads to secretion of inflammatory mediators. HIV-1 Env signaling through these pathways may contribute to dysregulation of uninfected macrophage functions, new target cell recruitment, or modulation of macrophage infection.

Coupling of the TCR to integrin activation by Slap-130/Fyb

SLAP-130/Fyb (SLP-76-associated phosphoprotein or Fyn-binding protein; also known as Fyb/Slap) is a hematopoietic-specific adapter, which associates with and modulates function of SH2-containing leukocyte phosphoprotein of 76 kilodaltons (SLP-76). T cells from mice lacking SLAP-130/Fyb show markedly impaired proliferation following CD3 engagement. In addition, the T cell receptor (TCR) in SLAP-130/Fyb mutant cells fails to enhance integrin-dependent adhesion. Although TCR-induced actin polymerization is normal, TCR-stimulated clustering of the integrin LFA-1 is defective in SLAP-130/Fyb-deficient cells. These data indicate that SLAP-130/Fyb is important for coupling TCR-mediated actin cytoskeletal rearrangement with activation of integrin function, and for T cells to respond fully to activating signals.

Dysfunction of microvascular endothelial cells induced by tumor necrosis factor (TNFalpha): cellular and molecular mechanism

The dysfunction of rat pulmonary microvascular endothelial cells (RPMVEC) induced by tumor necrosis factor alpha (TNFalpha) was investigated in cell culture. The TNFalpha concentrations added into culture were 1000-5000 u/ml. The study was done at different steps as follows: (1) cell proliferation dynamic, (2) coagulation and anti-coagulation, (3) adhesive molecule, (4) nitric oxide (NO), (5) oncogens, and (6) apoptosis. It was concluded that attention should be paid to the metabolic disorder and dysfunction of RPMVEC induced by TNFalpha which can not be found easily according to the morphological changes. This might be the common pathway in the pathogenesis of some diseases related to TNFalpha.

A novel human tumor necrosis factor alpha mutant showed potent antitumor activity and reduced toxicity in vivo

AIM

To study the antitumor activity and systemic toxicity of human tumor necrosis factor alpha (hTNFalpha) mutant M2 (R2K-N30S-R32W-L157F-hTNFalpha).

METHODS

Mouse sarcoma S180 tumors and hepatoma HAC tumors were implanted into mice, and human urocyst carcinoma CP-3 tumors were implanted into nude mice. The xenografted mice were injected with wild-type hTNFalpha and its mutant M2 at different doses. After 7 d (mice) or 10 d (nude mice) of injection, the tumor weight was measured to calculate the inhibition rate of hTNFalpha and M2. Systemic toxicity experiments were done on Rhesus monkeys by injecting them with wild-type hTNFalpha and mutant M2 respectively for 10 consecutive d. Observations were made on the monkeys both before and after the injection.

RESULTS

For mice implanted with sarcoma S180 and hepatoma HAC tumors, the inhibition rate of M2 was similar to that of wild-type hTNFalpha at the dose of 0.025 mg/kg, while for nude mice implanted with human urocyst carcinoma CP-3, the inhibition rate of M2 (45.5 %) was much higher than that of wild-type hTNFalpha (15.5 %). When the dose came to 0.25 and 2.5 mg/kg respectively, however, the inhibition rate of M2 greatly increased (the highest was 75.9 %). The tests of systemic toxicity of hTNFalpha and its mutant M2 in monkeys proved that M2 presented lower toxicity than wild-type hTNFalpha did.

CONCLUSION

hTNFalpha mutant M2 not only presented higher antitumor activity than wild-type hTNFalpha did on mouse tumor (S180 and HAC)- and human tumor (CP-3)-implanted mice, but also showed lower systemic toxicity in the Rhesus monkey.

A staggered-grid finite-difference method with perfectly matched layers for poroelastic wave equations

A particle velocity-strain, finite-difference (FD) method with a perfectly matched layer (PML) absorbing boundary condition is developed for the simulation of elastic wave propagation in multidimensional heterogeneous poroelastic media. Instead of the widely used second-order differential equations, a first-order hyperbolic leap-frog system is obtained from Biot's equations. To achieve a high accuracy, the first-order hyperbolic system is discretized on a staggered grid both in time and space. The perfectly matched layer is used at the computational edge to absorb the outgoing waves. The performance of the PML is investigated by calculating the reflection from the boundary. The numerical method is validated by analytical solutions. This FD algorithm is used to study the interaction of elastic waves with a buried land mine. Three cases are simulated for a mine-like object buried in "sand," in purely dry "sand" and in "mud." The results show that the wave responses are significantly different in these cases. The target can be detected by using acoustic measurements after processing.

[Separation of standard proteins and actual samples using cross-axis counter current chromatography]

A system of m (12.5% PEG8000): m (25% K2HPO4) = 1:1 was used to separate two kinds of standard proteins, glycoprotein in Morchella esculenta (L.) and glycoprotein in Lycium barbarum (L.), the upper phase was used as stationary phase, and the lower phase was used as mobile phase. The revolution speed was 500 r/min and the flow rate was 60 mL/h. In comparing with high performance liquid chromatography, cross-axis counter current chromatography can increase load capacity without loss of resolution. The advantage of this method was verified, indicating that cross-axis counter current chromatography was a useful method for biopolymer separation.

Fast spectral-domain method for acoustic scattering problems

This paper presents the application of the conjugate-gradient (CG) fast Fourier transform (FFT) (CG-FFT) method and the CG nonuniform FFT (CG-NUFFT) method for the integral equation arising from acoustic scattering problems. In the conventional method of moments (MoM) for integral equations, the CPU and memory requirements are O(N3) and O(N2), respectively, where N is the number of unknowns in the problem. The CG-FFT method, which combines the iterative conjugate-gradient method with FFT, reduces these requirements to O(KN log2 N) and O(N), respectively, where K is the number of CG iterations. The CG-NUFFT method differs from the CG-FFT method in that it makes use of nonuniform FFT algorithms instead of FFT to allow a nonuniform discretization. Therefore, the CG-NUFFT method can solve the integral equation with both uniform and nonuniform grid while retaining the efficiency of the CG-FFT method. These two methods are applied to solve for two-dimensional constant density acoustic scattering problems. Numerical results demonstrate that they can solve much larger problems than the MoM.

High-density lipoproteins from human alcoholics exhibit impaired reverse cholesterol transport function

We have previously shown that chronic alcohol consumption leads to inhibition of sialylation of apolipoprotein E (apo E) that results in its impaired binding to high-density lipoprotein (HDL) molecule. Because apo E plays a major role in reverse cholesterol transport (RCT), we speculated that ethanol-mediated formation of HDL molecules without apo E may affect the RCT process. Therefore, we have investigated whether the RCT function of HDL is affected in chronic alcoholics with or without liver disease compared with nondrinkers. HDL was isolated from fasting plasma of normal subjects, n = 9 (nondrinkers), chronic alcoholics, n = 8 (ALC), and chronic alcoholics with liver disease, n = 6 (ALD). A portion of HDL sample from each subject was evaluated for its cholesterol efflux capacity from [3H]cholesterol oleate preloaded mouse macrophages. The remaining portion of each HDL sample was labeled with [3H]cholesterol oleate and evaluated for its ability to deliver cholesterol to the liver using HepG2 cells in culture. Cholesterol efflux capacity of HDLs was decreased by 83% (P < .0002) in alcoholics without liver disease and by 84% (P < .0006) in alcoholics with liver disease compared with the HDLs from nondrinkers. The capacities of HDLs to deliver cholesterol to the liver were decreased by 54% (P < .005) in alcoholics without liver disease and by 64% (P < .005) in alcoholics with liver disease compared with the HDLs from nondrinkers. The fact that further complications by liver disease in alcoholic subjects did not significantly exacerbate the extent of impairment in RCT function of HDL suggest that alcohol per se is responsible for its deleterious effects on RCT. Significantly, plasma HDL apo E concentration relative to that of apo A1 (apo E/apo A1 ratio) was also decreased by 31% to 32% (P < .0005) in alcoholics without or with liver disease compared with nondrinkers. It is therefore concluded that chronic alcohol consumption adversely affects the RCT function of HDL by altering its association with apo E due to ethanol-induced desialylation of apo E.

Chemokine signaling and HIV-1 fusion mediated by macrophage CXCR4: implications for target cell tropism

To better understand CXCR4 function on macrophages and the relationship between coreceptor use and macrophage tropism among diverse HIV-1 isolates, we analyzed macrophage pathways involved in Env-mediated fusion, productive HIV-1 infection, and chemokine-elicited signaling. We found that both CXCR4 and CCR5 transduced intracellular signals in monocyte-derived macrophages, activating K+ and Cl- ion channels and elevating intracellular calcium in response to their chemokine ligands stromal cell-derived factor-1alpha and macrophage inflammatory protein-1beta, respectively. The prototype T-tropic X4 strain IIIB infected macrophages poorly, and this was associated with failure of the IIIB Env to fuse efficiently with target macrophages despite functional CXCR4. In contrast, several primary X4 isolates mediated efficient CXCR4-dependent fusion and productive macrophage infection. Several R5X4 strains could fuse with and infect macrophages through both CCR5 and CXCR4. Thus, macrophages express functional CXCR4 and CCR5 but primary and prototype X4 isolates differ in their ability to utilize macrophage CXCR4. Isolates classified as X4 based on coreceptor use may be phenotypically either T-tropic or dual-tropic and, conversely, phenotypically dual-tropic isolates may be either R5X4 or X4 based on coreceptor use.

HIV-1 gp120 and chemokines activate ion channels in primary macrophages through CCR5 and CXCR4 stimulation

HIV type 1 (HIV-1) uses the chemokine receptors CCR5 and CXCR4 as coreceptors for entry into target cells. Here we show that the HIV-1 envelope gp120 (Env) activates multiple ionic signaling responses in primary human macrophages, which are important targets for HIV-1 in vivo. Env from both CCR5-dependent JRFL (R5) and CXCR4-dependent IIIB (X4) HIV-1 opened calcium-activated potassium (K(Ca)), chloride, and calcium-permeant nonselective cation channels in macrophages. These signals were mediated by CCR5 and CXCR4 because macrophages lacking CCR5 failed to respond to JRFL and an inhibitor of CXCR4 blocked ion current activation by IIIB. MIP-1beta and SDF-1alpha, chemokine ligands for CCR5 and CXCR4, respectively, also activated K(Ca) and Cl(-) currents in macrophages, but nonselective cation channel activation was unique to gp120. Intracellular Ca(2+) levels were also elevated by gp120. The patterns of activation mediated by CCR5 and CXCR4 were qualitatively similar but quantitatively distinct, as R5 Env activated the K(Ca) current more frequently, elicited Cl(-) currents that were approximately 2-fold greater in amplitude, and elevated intracellular Ca(+2) to higher peak and steady-state levels. Env from R5 and X4 primary isolates evoked similar current responses as the corresponding prototype strains. Thus, the interaction of HIV-1 gp120 with CCR5 or CXCR4 evokes complex and distinct signaling responses in primary macrophages, and gp120-evoked signals differ from those activated by the coreceptors' chemokine ligands. Intracellular signaling responses of macrophages to HIV-1 may modulate postentry steps of infection and cell functions apart from infection.

Effect of dietary omega-3 fatty acids and chronic ethanol consumption on reverse cholesterol transport in rats

We previously showed that chronic ethanol feeding leads to a decrease of apolipoprotein E (apoE) in high-density lipoprotein (HDL), whereas supplementing this diet with 2.8% of total dietary calories as omega3-fatty acids (omega3FAs) restores HDL-apoE to the control values. Since HDL containing apoE plays a major role in reverse cholesterol transport (RCT), we measured the effects chronic ethanol intake and omega3-FAs on RCT in the present study. Four groups of rats, control normal fat (CN), alcohol-normal fat (AN), control omega3FA fat (CF), and alcohol-omega3FA fat (AF), were fed their respective diets for 8 weeks, after which hepatocytes and HDLs from each group were evaluated for RCT capacity (cholesterol efflux from macrophages and uptake by liver cells). Compared with the control diet (CN), chronic ethanol (AN) feeding inhibited the cholesterol efflux capacity of HDL by 21% (P < .01), whereas omega3FA feeding (2.8% of total dietary calories) stimulated this capacity by 79% (P < .01) and 25% (P < .01) in CF and AF rats, respectively. With respect to cholesterol uptake by the liver, there were no significant 3-way or 4-way interactions between the 4 factors, HDL-alcohol, HDL-fish oil, hepatocyte-alcohol, and hepatocyte-fish oil. The main effects for HDL-alcohol, HDL-fish oil, and hepatocyte-alcohol were all highly significant (P = .0001, .0001, and .007, respectively). There was a significant HDL-alcohol and HDL-fish oil interaction (P = .0001). Hepatocyte-alcohol was not a factor in any 2-way interactions. Our study indicates no evidence of an interaction between the effects of omega3FAs and the effects of alcohol on hepatocytes in terms of RCT function. Thus, feeding as little as 2.8% of the total dietary calories as omega3FA not only restored the impaired RCT function of HDL caused by chronic ethanol intake, but also enhanced by severalfold the ability of HDL to promote RCT even in normal animals.

Nonuniform fast Hankel transform (NUFHT) algorithm

We investigate the fast computation of Hankel transforms on a set of nonuniformly spaced sample points. Previous fast Hankel transform (FHT) algorithms require the sample points to distribute uniformly in a logarithmic scale. This limitation is removed here by the use of the newly developed, to our knowledge, nonuniform fast Fourier transform algorithm. The resulting nonuniform FHT algorithm has a much higher accuracy than the previous FHT algorithms and provides important flexibility in many applications.

Receptor avidity and costimulation specify the intracellular Ca2+ signaling pattern in CD4(+)CD8(+) thymocytes

Thymocyte maturation is governed by antigen-T cell receptor (TCR) affinity and the extent of TCR aggregation. Signals provided by coactivating molecules such as CD4 and CD28 also influence the fate of immature thymocytes. The mechanism by which differences in antigen-TCR avidity encode unique maturational responses of lymphocytes and the influence of coactivating molecules on these signaling processes is not fully understood. To better understand the role of a key second messenger, calcium, in governing thymocyte maturation, we measured the intracellular free calcium concentration ([Ca2+]i) response to changes in TCR avidity and costimulation. We found that TCR stimulation initiates either amplitude- or frequency-encoded [Ca2+]i changes depending on (a) the maturation state of stimulated thymocytes, (b) the avidity of TCR interactions, and (c) the participation of specific coactivating molecules. Calcium signaling within immature but not mature thymocytes could be modulated by the avidity of CD3/CD4 engagement. Low avidity interactions induced biphasic calcium responses, whereas high avidity engagement initiated oscillatory calcium changes. Notably, CD28 participation converted the calcium response to low avidity receptor engagement from a biphasic to oscillatory pattern. These data suggest that calcium plays a central role in encoding the nature of the TCR signal received by thymocytes and, consequently, a role in thymic selection.