Sources of elevated organic acids in the mountainous background atmosphere of southern China.

Formic acid (FA) and acetic acid (AA) are pivotal organic acids in the troposphere, significantly influencing atmospheric chemistry. However, their abundance and sources in the mountainous background atmosphere remain underexplored. We undertook continuous measurements of FA and AA in Nanling mountains, southern China, during autumn 2020 using a high-resolution time-of-flight chemical ionization mass spectrometer (HR-ToF-CIMS). Both acids registered higher concentrations than in other global high-altitude or forested locations, averaging at 0.89 (max: 3.91) and 0.95 (max: 3.52) ppbv for FA and AA, respectively. High concentrations of FA and AA in this forested background area arose from secondary formation and biomass burning, collectively contributing 71 % to 89 %. During episodes, FA and AA concentrations surged 2-3 times, owing to the enhanced atmospheric oxidation capacity. The secondary FA production was predominantly due to isoprene oxidation among the VOC precursors studied. However, observed inconsistencies between calculated and actual FA concentrations suggest overlooked precursors or mechanisms warranting further investigation. Our findings can enhance the understanding of organic acid characteristics and the interplay of biogenic and anthropogenic sources in the background atmosphere.

Cryo-electron microscopy structure and translocation mechanism of the crenarchaeal ribosome.

Archaeal ribosomes have many domain-specific features; however, our understanding of these structures is limited. We present 10 cryo-electron microscopy (cryo-EM) structures of the archaeal ribosome from crenarchaeota Sulfolobus acidocaldarius (Sac) at 2.7-5.7 Å resolution. We observed unstable conformations of H68 and h44 of ribosomal RNA (rRNA) in the subunit structures, which may interfere with subunit association. These subunit structures provided models for 12 rRNA expansion segments and 3 novel r-proteins. Furthermore, the 50S-aRF1 complex structure showed the unique domain orientation of aRF1, possibly explaining P-site transfer RNA (tRNA) release after translation termination. Sac 70S complexes were captured in seven distinct steps of the tRNA translocation reaction, confirming conserved structural features during archaeal ribosome translocation. In aEF2-engaged 70S ribosome complexes, 3D classification of cryo-EM data based on 30S head domain identified two new translocation intermediates with 30S head domain tilted 5-6° enabling its disengagement from the translocated tRNA and its release post-translocation. Additionally, we observed conformational changes to aEF2 during ribosome binding and switching from three different states. Our structural and biochemical data provide new insights into archaeal translation and ribosome translocation.

Archaeal ribosomes display variations in their ribosomal proteins and ribosomal RNA (rRNA) expansion segments (ESs). Protein translation in archaea combines features in both bacterial and eukaryotic translation. In this study, we present 10 cryo-electron microscopy structures of the archaeal ribosome from crenarchaeota Sulfolobus acidocaldarius (Sac). The 50S and 30S subunit structures present 3 novel ribosomal proteins and 12 rRNA ESs. The 70S Sac ribosome structures were captured in seven distinct functional states, including pre-, intermediate- and post-translocation states. Specifically, we identified two novel translocation intermediates, in which the 30S subunit head domain tilts outward to release the translocated P-site transfer RNA. The structures of archaeal ribosomes provide insights into the archaeal translation and ribosome translocation.

Anthropogenic Pollutants Induce Changes in Peroxyacetyl Nitrate Formation Intensity and Pathways in a Mountainous Background Atmosphere in Southern China.

Mountainous background areas are typically considered to have a clean atmosphere where peroxyacetyl nitrate (PAN) can be decomposed. This study demonstrated that PAN was photochemically formed with a simulated production rate of 0.28 ± 0.06 ppbv h-1 in the Nanling mountains (1690 m a.s.l.) of South China and that net PAN formation was dependent on both volatile organic compounds (VOCs) and NOx precursors (transition regime). In contrast to dominated acetaldehyde oxidation in previous urban and rural research, PAN at Nanling was primarily formed by methylglyoxal (38%), acetaldehyde (28%), radicals (20%), and other oxygenated volatile organic compounds (OVOCs) (13%). Moreover, when polluted air masses invaded the Nanling mountains, the PAN production rate was altered, primarily because anthropogenic aromatics intensified PAN formation via the oxidized pathways of methylglyoxal, other OVOCs, and radicals. Finally, net PAN formation at Nanling reduced the hydroxyl radical level by consuming NOx, impaired local radical cycling, and thereby suppressed local O3 production. This suppressing effect was exacerbated on polluted days. The findings of this study deepen our understanding of PAN photochemistry and the impact of anthropogenic intrusions on the background atmosphere of mountainous regions.

Investigation of Left Ventricular Strain and Its Morphological Basis During Different Stages of Diastolic and Systolic Dysfunction in Spontaneously Hypertensive Rat.

BACKGROUND: Myocardial fibrosis plays an important role in the pathogenesis of hypertensive cardiac dysfunction, and myocardial strain could detect early systolic abnormalities when left ventricular ejection fraction (LVEF) is preserved. The aim of this study was to investigate the characteristics of left ventricular multidirectional strain during different stages of heart dysfunction and the possible morphological basis in spontaneously hypertensive rats (SHRs). METHODS: SHRs and Wistar-Kyoto (WKY) rats were randomly divided into cages and observed for 3-25 months. Echocardiographic measurements, LV + dp/dtmax and left ventricular end-diastolic pressure (LVEDP), and histological collagen volume fraction (CVF) were observed in all rats. RESULTS: According to LVEF and LVEDP, SHRs were divided into normal cardiac function group (group A), diastolic dysfunction group (group B1), and systolic dysfunction group (group B2). In group A, myocardial strain and CVF showed no difference compared with the control group. In group B1, global longitudinal strain (GLS) and endocardial longitudinal strain (SL-endo) were lower than those in group A CVF-endo was increased (all P < 0.05). In group B2, global and layer-specific strain decreased significantly, along with the increased CVF-endo and CVF-epi (all P < 0.05). The decrease of GLS and SL-endo was moderately correlated with the increase of CVF-endo. The reduction of LVEF was correlated with the decrease of SC-endo (r = 0.65, P < 0.01). CONCLUSIONS: Pathological myocardial fibrosis associated with hypertension develops from the inner to outer layer of myocardium, which is coincident with the impairment of myocardial deformation, where longitudinal strain is involved firstly and LVEF declines when all directions of strain are reduced.

MXene monolayer Mn2ZnN2: a promising robust intrinsic half-metallic nanosheet.

Two-dimensional half-metallic ferromagnets are promising in spintronics. In recent years, the half-metallicity and the magnetic properties of the MXene materials have been the research hotspots of new materials due to their unique crystal characteristics and wide applications. In this paper, the MXene nanosheet Mn2ZnN2was predicted as a kind of robust intrinsic half-metallic nanosheet whose magnetic moment per unit is the integer 6.00µBbased on the first principles calculations. The half-metallic character and the magnetic moment of this nanosheet mainly result from the spin-polarized Mn-ions induced by the crystal field. If the absolute biaxial compression strain is lower than 3.0%, the half-metallicity remains well and the magnetic moment per unit is always 6.00µB, indicating that its half-metallicity and magnetic properties are stable within a certain pressure range. More importantly, the magnetic moment per unit is elevated from 6.00µBto 9.00µBand the half-metallic energy gap increases evidently after an electron is removed from this nanosheet, suggesting that the half-metallicity and magnetic properties of this nanosheet may be improved via tuning its charge state.

A comparison study of applying natural iron minerals and zero-valent metals as Fenton-like catalysts for the removal of imidacloprid.

Natural iron minerals and zero-valent metals have been widely tested as catalysts for the Fenton-like process, but the systematical comparison study about their catalytic performance was rarely conducted, and the risk of the secondary pollution of toxic heavy metals was still not uncertain. In this paper, a comparison study of applying pyrite, ilmenite, vanadium titano-magnetite (VTM), zero-valent iron (ZVI), and zero-valent copper (ZVC) as Fenton-like catalysts for the removal of imidacloprid was performed. The results showed that ZVI exhibited the highest activity among the recyclable solid catalysts with a removal rate of 96.8% at initial pH 3 using 10.78 mmol/L H2O2, due to iron corrosive dissolution. Vanadium titano-magnetite (VTM) exhibited the best activity at first use among tested minerals but with low reusability. Pyrite with stable morphology showed a medium but sustainable ability to degrade imidacloprid, achieving a removal rate of 10.5% in the fifth use. The reaction much favored the acidic condition of initial pH around 2 or 3. Meanwhile, there was a significant positive correlation between removal efficiency and dissolved Fe or Cu concentration. Pyrite was considered to be a promising catalyst in Fenton-like reaction. It was suggested that the system proceeded predominantly through a homogeneous route via dissolved Fe or Cu ions. Except ZVC and VTM, other tested catalysts showed the low possibility of causing secondary pollution of toxic metals in the application of Fenton-like process.

Therapeutic Observation of ZHU Lian's Acupuncture plus Wen Ren Tiao Shu Method in Treating Anovulatory Infertility / 上海针灸杂志

Objective To observe the efficacy difference between ZHU Lian's acupuncture plusWen Ren Tiao Shu method (warming the Conception Vessel and regulating back-Shu points) and ovulation drugs in treating anovulatory infertility.Method Seventy patients were randomized into an observation group and a control group, 40 cases each. The control group was given ovulation triggering medications; the observation group was intervened by ZHU Lian's acupuncture plusWen Ren Tiao Shu method, with Tianshu (ST25), Zigong (EX-CA 1), Guanyuan (CV4), Xuehai (SP10), Zusanli (ST36), Sanyinjiao (SP6), Ganshu (BL18), Pishu (BL20), Sanjiaoshu (BL22) and Shenshu (BL23) selected, once per day, 10 sessions as a course of treatment. The two groups were observed for 3 menstrual cycles. The symptoms score of traditional Chinese medicine (TCM), menstruation score, basal body temperature (BBT), and ovulation rate by gynecological scanning were compared before and after the treatment, and the clinical efficacies were compared between the two groups.Result The TCM symptoms score changed significantly after the intervention in the observation group (P<0.05); the TCM symptoms score didn't show significant change after the treatment in the control group (P>0.05); after the treatment, there was a significant difference in comparing the symptoms score between the two groups (P<0.01); there was a significant difference in comparing the BBT between the two groups after the intervention (P<0.05); according to Chi-square test, after the treatment, the difference in ovulation rate between the two groups was statistically significant (P<0.05); the total effective rate was 94.3% in the observation group, higher than 82.9% in control group.ConclusionZHU Lian's acupuncture plusWen Ren Tiao Shu method can improve the symptoms of anovulatory fertility, increase the conception rate, and reduce adverse reactions; this method can produce a more significant efficacy than oral administration of Western medications in treating anovulatory fertility.

Therapeutic Observation of ZHU Lian's Acupuncture plus Wen Ren Tiao Shu Method in Treating Anovulatory Infertility / 上海针灸杂志

Objective To observe the efficacy difference between ZHU Lian's acupuncture plusWen Ren Tiao Shu method (warming the Conception Vessel and regulating back-Shu points) and ovulation drugs in treating anovulatory infertility.Method Seventy patients were randomized into an observation group and a control group, 40 cases each. The control group was given ovulation triggering medications; the observation group was intervened by ZHU Lian's acupuncture plusWen Ren Tiao Shu method, with Tianshu (ST25), Zigong (EX-CA 1), Guanyuan (CV4), Xuehai (SP10), Zusanli (ST36), Sanyinjiao (SP6), Ganshu (BL18), Pishu (BL20), Sanjiaoshu (BL22) and Shenshu (BL23) selected, once per day, 10 sessions as a course of treatment. The two groups were observed for 3 menstrual cycles. The symptoms score of traditional Chinese medicine (TCM), menstruation score, basal body temperature (BBT), and ovulation rate by gynecological scanning were compared before and after the treatment, and the clinical efficacies were compared between the two groups.Result The TCM symptoms score changed significantly after the intervention in the observation group (P<0.05); the TCM symptoms score didn't show significant change after the treatment in the control group (P>0.05); after the treatment, there was a significant difference in comparing the symptoms score between the two groups (P<0.01); there was a significant difference in comparing the BBT between the two groups after the intervention (P<0.05); according to Chi-square test, after the treatment, the difference in ovulation rate between the two groups was statistically significant (P<0.05); the total effective rate was 94.3% in the observation group, higher than 82.9% in control group.ConclusionZHU Lian's acupuncture plusWen Ren Tiao Shu method can improve the symptoms of anovulatory fertility, increase the conception rate, and reduce adverse reactions; this method can produce a more significant efficacy than oral administration of Western medications in treating anovulatory fertility.

Anti-colorectal cancer effects of tripolinolate A from Tripolium vulgare / 中国天然药物

Tripolinolate A (TLA) is recently identified as a new compound from a halophyte plant Tripolium vulgare and has been shown to have significant in vitro activity against the proliferation of colorectal cancer and glioma cells. This study was designed to further investigate the effects of TLA on the proliferation of human normal cells, and the apoptosis and cell cycle in colorectal cancer cells, and the growth of tumors in the colorectal cancer-bearing animals. The data obtained from this study demonstrated that: 1) TLA had much less cytotoxicity in the human normal cells than the colorectal cancer cells; 2) TLA remarkably induced apoptosis in the human colorectal cancer cells and blocked cell cycle at G/M phase, and 3) TLA had significant anti-colorectal cancer activity in the tumor-bearing animals.

Research progress on potential liver toxic components in traditional Chinese medicine / 中国中药杂志

In recent years, the proportion of traditional Chinese medicine in scientific research and its clinical use increased gradually. The research result also becomes more and more valuable, but in the process of using traditional Chinese medicine, it also needs to pay more attention. With the gradual deepening of the toxicity of traditional Chinese medicine, some traditional Chinese medicines have also been found to have the potential toxicity, with the exception of some traditional toxicity Chinese medicine. Traditional Chinese medicine in the growth, processing, processing, transportation and other aspects of pollution or deterioration will also cause the side effects to the body. Clinical practice should be based on the theory of traditional Chinese medicine to guide rational drug use and follow the symptomatic medication, the principle of proper compatibility. The constitution of the patients are different, except for a few varieties of traditional Chinese medicines are natural herbs with hepatotoxicity, liver toxicity of most of the traditional Chinese medicine has idiosyncratic features. The liver plays an important role in drug metabolism. It is easy to be damaged by drugs. Therefore, the study of traditional Chinese medicine potential liver toxicity and its toxic components has become one of the basic areas of traditional Chinese medicine research. Based on the review of the literatures, this paper summarizes the clinical classification of liver toxicity, the pathogenesis of target cell injury, and systematically summarizes the mechanism of liver toxicity and toxic mechanism of traditional Chinese medicine. This paper provided ideas for the study of potential liver toxicity of traditional Chinese medicine and protection for clinical safety of traditional Chinese medicine.

Dendritic Cells Promote the Proliferation of Peripheral Blood CRTH2 Cells (CD4(+)CD294(+)Th2) and Help B Cells to Secrete Immunoglobulin / 中国实验血液学杂志

Objective：To investigate the promotive effect of dendritic cells(DCs) on proliferation of CRTH2 (CD4(+)CD294(+)Th2) cells and the influence of CRTH2 cells on secretion of immunoglobulin from B cells so as to provide a new approach for amplification and sorting of Th2 cells. Methods：DCs were induced from peripheral blood mononuclear cells, then the loaded-BCGV-Ag-DCs were cocultured with T cells, and the mixed lymphocyte reaction(MLR) was performed by CCK8 method. The phenotypes of DCs and CRTH2 cells were detected by flow cytometry. CRTH2 cells sorted by MACS were co-cultured with B cells for 5 days to detect the secretion of immunoglobulin. Results：The subsets and absolute number CRTH2 cells were significantly increased by loaded-BCGV-Ag-DCs. The levels of IgG, IgA and IgE were higher increased in supernatant of CRTH2 and B cell co-culture system than that in control group or that in transwell group(P<0.05). Conclusion：The proliferation of CRTH2 cells can be greatly promoted by loaded-BCGV-Ag-DCs, and the CRTH2 cells can help B cells to secrete IgG, IgA and IgE.

Comparison clinical efficacy of 3% hypertonic saline solution with 20% mannitol in treatment of intracranial hypertension in patients with aneurysmal subarachnoid hemorrhage / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To compare the efficacy of 3% hypertonic saline solution with 20% mannitol in treatment of intracranial hypertension in patients with aneurysmal subarachnoid hemorrhage.</p><p><b>METHODS</b>An alternating treatment protocol was used to compare the efficacy of 160 mL 3% hypertonic saline solution (HSS) with 150 mL 20% mannitol for episodes of increased intracranial pressure (ICP) in patients with aneurysmal subarachnoid hemorrhage. The dependent variables were the extent and duration of reduction of increased ICP after each event.</p><p><b>RESULTS</b>Both 3% HSS and 20% mannitol rapidly decreased the ICP in patients with aneurysmal subarachnoid hemorrhage (P <0.01). No difference between two medications in the extent of duration of ICP and reduction of action (P >0.05).</p><p><b>CONCLUSION</b>3% HSS should be considered as the first-line osmotic drug in treatment of intracranial hypertension in patients with aneurysmal subarachnoid hemorrhage.</p>

Tissue culture of Sophora tonkinensis Gapnep. and its quality evaluation.

BACKGROUND: Sophora tonkinensis Gapnep. is an important rare medicinal plant in China. There were only a few papers on the rapid propagation of S. tonkinensis through in vitro tissue culture, and still no report focuses on the quality analysis of in vitro tissue culture plantlets. MATERIALS AND METHODS: The different concentrations of 6-benzylaminopurine (BAP), kinetin (KT), and indole-3-acetic acid (IAA) were used to establish and screen the optimal rapid propagation technology of S. tonkinensis by orthogonal test; the different concentrations of a-naphthalene acetic acid (NAA), indole-3-butyric acid (IBA), and ABT rooting power (ABT) were used to screen the optimal rooting technology. For quality evaluation of tissue culture plants, three different sites were chose to finish planting experiment. The leaf characteristics, radix ex rhizoma yield, and contents of matrine and oxymatrine were evaluated, respectively, to provide evidence of high yield and good qualities of tissue culture plants. RESULTS: A large number of buds could be induced directly from epicotyl and hypocotyl explants on the Murashige and Skoog (MS) medium supplemented with 1.5 mg/l BAP, 0.5 mg/l IAA, and 0.5 mg/l KT; the best root induction medium was solid MS medium at half the macronutrient concentration supplemented with 1.0 mg/l NAA, 0.4 mg/l IBA, and 0.1 mg/l ABT. The rooting rate was 98%. All tissue culture plants showed normal leaf characteristics. Tissue culture plants from two sites possessed higher radix ex rhizoma yield and overall productivity of matrine and oxymatrine than those of seed plants. CONCLUSION: Tissue culture is a rapid, effective, and convenient propagation method for S. tonkinensis, and the quality of S. tonkinensis tissue culture plants meets the requirement of quality standard of China Pharmacopoeia (edition 2010), the crude drug from S. tonkinensis tissue culture plants will be suitable for substituting the crude drug from seed plants.

Analysis of the difference in the tissue surfaces between the old and new upper complete dentures / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the reduction in residual ridges of maxillary edentulous models duplicated from old and new complete dentures using the 3-D data analysis.</p><p><b>METHODS</b>Twenty-six pairs of maxillary edentulous models copied from the fitting surfaces of new and old upper complete dentures were selected for this study. The 3-D data were collected with a laser scanning system. The data were matched using Geomagic Studio 8 and Rapidform2006 software and then the fitting surfaces of new complete dentures were analyzed in comparison with old ones.</p><p><b>RESULTS</b>The total amount of morphologic change of fitting surface [(39.8+/-14.2)%] was greater than the change of width [(28.2+/-16.0)%]; the area reduction of the residual ridge in anterior region [(43.0+/-15.2)%] was larger than that in posterior region [(36.1+/-14.1)%]; and the area reduction of residual ridge in buccal aspect [(42.9+/-13.8)%] was larger than that in lingual aspect [(35.5+/-15.2)%]. All the differences were statistically significant (P<0.05).</p><p><b>CONCLUSIONS</b>The results of this study reveal that 3-D analysis of the whole change of the residual ridge is significant and verify that the residual ridge resorption of edentulous maxilla in three dimensions is greater in buccal aspect than in lingual aspect and greater in anterior region than in posterior region.</p>

Effect of resuscitation after selective cerebral ultraprofound hypothermia on expressions of nerve growth factor and glial cell line-derived neurotrophic factor in the brain of monkey / 神经科学通报·英文版

<p><b>OBJECTIVE</b>To investigate the expression of nerve growth factor (NGF) and glial cell line-derived neurotrophic factor (GDNF) in monkeys of resuscitation after selective cerebral ultraprofound hypothermia and blood flow occlusion.</p><p><b>METHODS</b>The monkeys were immediately removed brain after death in operation of group A (identical temperature perfusion group) and group B (ultraprofound hypothermia perfusion group). Immunohistochemical technique was used to determine frontal cellular expression of NGF and GDNF. Statistics were analyzed by ANOVA analyses with significance level at P < 0.05.</p><p><b>RESULTS</b>The expressions of NGF and GDNF in the group B were significantly higher than those in the group A (P < 0.05).</p><p><b>CONCLUSION</b>NGF and GDNF increased significantly in the monkeys of resuscitation after selective cerebral ultraprofound hypothermia and blood flow occlusion. It may be a protective mechanism for neuron survival and neural function recovery.</p>

Effects of Goutengsan on model of Alzheimer dementia in rats by AlCl3 / 中国中药杂志

<p><b>OBJECTIVE</b>Observe the effects of Goutengsan on SOD, MAO-B, GSH-PX, NO, LDH, index of brain, rate of death and so on in rats to study therapeutic effects and mechanism of Goutengsan on Alzheimer dementia (AD) model.</p><p><b>METHOD</b>One hundred and twenty rats were randomly divided into 6 groups, 3 experimental groups of which were daily administrated with Goutengsan extract whereas the model and control groups were given NS (0.01 mL x g(-1)). Aniracetam at 0.1 g x kg(-1) served as a positive control. At the 5th day after administration, all groups except the control were administrated (ip) with AlCl3 (100 mg x kg(-1) ) for successive 50 days at 1 day interval. After administration, the death rate, body weight, training scores, brain index, MAO-B, SOD, GSH-Px in brain and NO, LDH in serum were determined.</p><p><b>RESULT</b>The brain index, SOD, GSH-Px activities as well as NO content of drug-treated groups were strikingly higher that of model group, and had not obvious difference from that of normal group except content of LDH was higher.</p><p><b>CONCLUSION</b>Goutengsan could increase the brain index, cut down the rate of death, stable increase of body weight, promote the endogenous antioxidant activity, enhance the clearance of lipid peroxide and other metabolic waste, inhibit the MAO-B activity, reduced the leakage of LDH and maintain the content of NO at a normal level. Therefore Goutengsan could protect cells, delay senile, improve symptoms of AD.</p>

The Cross-section Study on the Obesity and Hypertension in Children Aged 6 to 12 yrs,in Shenzhen / 中国慢性病预防与控制

Objective To investigate the prevalence of hypertension and obesity and their main influencial factors among 6～12 years old children in Shenzhen.Method 1 140 children aged from 6 to 12 years old in 4 schools in Shenzhen were sampled by random cluster sampling,and their systolic blood pressure(SBP),diastolic blood pressure(DBP),body height,weight and other morphological parameters were measured.Results The prevalent rate of hypertension was 9.4%(8.6% for boys and 10.2% for girls);Rate of overweight and obesity for boys were 13.25% and 13.72,respectively,and the girl were 9.09% and 8.10%,respectively.There were a increasing trend toward SBP and DBP with age,especially SBP.After adjusted with age and gender,the partial correlation coefficients between BMI and SBP,DBP were 0.462 and 0.357,respectively(P

Amelioration of streptozotocin-induced diabetes in mice using human islet cells derived from long-term culture in vitro.

BACKGROUND: Long-term maintenance of the phenotype of beta cells in vitro is difficult. The objective of this study was to examine an in vitro method for preserving the capacity of adult human beta cells to express insulin. We evaluated the use of long-term cultured islet cells for the treatment of diabetic SCID mice. METHODS: Human islets were isolated from cadaveric donors. The islets were cultured as monolayers and clusters in repeating cycles for 4 months. Thereafter, the cells were tested in vitro for their capacity to express insulin and to secrete insulin in response to glucose challenge. Finally, the cluster-cultured cells were transplanted under the kidney capsule and into the kidney tissue in streptozotocin (STZ)-induced diabetic SCID mice. RESULTS: Approximately 3.6% of cultured islet cells in cluster phase expressed insulin at 4 months and this was confirmed using immuno-gold-labeling electron microscopy. The cultured islet cells secreted insulin in response to glucose challenge in a dose-dependent manner. After transplantation, the islet cells redifferentiated and generated >20% insulin positive cells. The 4-month cultured cells rendered the blood glucose level near normal in mild diabetic mice (7.25 mM+/-1.595 vs. 15.225 mM+/-2.55, P<0.0025). CONCLUSION: It is possible to preserve the capacity of adult human islets to express insulin over a 4-month period in vitro, and this capacity was enhanced significantly by transplantation into SCID mice. The described system will be useful in studies of beta cell proliferation and differentiation.

MRI study of acute radiation-induced hepatic injury with super paramagnetic iron oxide enhancement in experimental model / 中华放射学杂志

Objective To investigate the MR imaging technique and features of acute radiation- induced hepatic injury with superparamagnetic iron oxide(SPIO)enhancement in a rabbit model.Methods On the 10th day after half-liver single 40 Gy X-ray irradiation,MR imaging before and after SPIO administration and pathologic study of 12 adult rabbits were performed.Results On the 10th post-irradiation day,TSE T_2 WI before SPIO enhancement,the irradiated liver of two rabbits showed relatively higher signal, and 1 showed slightly lower signal.With SPIO enhancement,the irradiated livers of 9 rabbits were found to be abnormal,manifesting as higher or slightly higher areas on multiple MR imaging sequences,especially the TFE T_1 WI sequence.Histological specimen with HE stain under light microscopy revealed occlusive injury of central veins(veno-occlusive disease,VOD)in each irradiated liver to some extent.Electron microscopy investigation of the irradiated liver disclosed intracellular edema,fibrin deposition,and widening of the Disse-space.Conclusion The early pathologic feature of the irradiated liver is occlusive injury of the central vein.MR imaging with SPIO enhancement is effective to valuate the early irradiation-induced liver injury.

Effects of Dayecai (Selaginella doedealeinii) and Chinese Livistona (Livistona chinensis)on the activity of Protein Kinase C / 中草药

Protein Kinase C (PKC ) was partially purified from rat brain by DEAE-52 column chromatography, and the effects of ethanol extracts of Selaginella doederleinii and Livistona chinensis on PKC activity were investigated.In order to verify the reliability of the assay system, the effect of polymyxin B, a known PKC inhibitor, on the activity of PKC was also tested. Results showed that the ethanol extract of S. doederleinii strongly inhibited PKC activity with IC50 2.2?g/ml. The ethanol extract of L. chinensis (100?g/ml ) inhibited PKC activity by 66.6%. Polymyxin B inhibited PKC activity with IC5017.7 U/ml.