An Environmental Dilemma for China During the COVID-19 Pandemic: The Explosion of Disposable Plastic Wastes

Plastic pollution control has been on top of the political agenda in China. In January 2020, China announced a phased ban on the production and usage of various types of single-use plastics as a solution to environmental pollution problems. However, the outbreak of COVID-19 seems to be a new obstacle to the ban on single-use plastic products. To basically satisfied the daily necessities and contain the spread of SARS-CoV-2 under the background of the regular epidemic prevention and control in China, online ordering, contactless delivery and wearing mask have become an important and feasible way of daily life. However, the unrestrained use of disposable plastic bags, lunch boxes and masks within the nationwide quarantine leads to hundreds of millions of plastics wastes every day. The potential environmental pollution caused by the use of disposable plastic products during the pandemic should arouse social concern. The Chinese government should manage environmental protection in parallel with anti-pandemic endeavors as the situation of the pandemic evolves.

     

应用激光电泳技术对MA737小鼠乳腺癌细胞膜表面电荷特性的研究

本工作应用激光多普勒电泳技术对ＭＡ７３７小鼠乳腺癌细胞膜表面电荷特性及高温（４２．５℃）对癌细胞的热效应进行了深入的研究。结果发现，ＭＡ７３７癌细胞的电泳迁移率（ＥＰＭ）明显高于相应正常细胞的ＥＰＭ（约２０％），表明癌细胞表面负电荷增高；实验发现唾液酸可能是ＭＡ７３７癌细胞膜表主要负电基团的来源之一。研究还发现，ＭＡ７３７癌细胞的热敏性比相应的正常细胞强，随高温受热时间的延长，癌细胞的ＥＰＭ呈下降趋势。     

球囊导管损伤后早期动脉平滑肌细胞的增殖

目的：研究动脉硬化早期中膜与内膜平滑肌细胞的增殖。方法：球囊导管损伤大鼠的颈总动脉后在电镜和光镜下观察其形态和生化指标变化。结果：术后24h 5-溴脱氧尿嘧啶尿苷阳性平滑肌细胞出现,阳性细胞率分别于术后第2,5d出现高峰。术后第2,3d迁移细胞的出现率最高。术后第3d,88.8%迁移细胞增殖细胞核抗原阳性。透射电子显微镜下,术后第3d中膜平滑肌细胞特别是内层的为合成型,并且与细胞外基质连接稀疏,基底膜、胶原纤维和弹性纤维被消失。结论：动脉损伤后,中膜平滑肌细胞呈高增殖性,由收缩型转变为合成型,与细胞外基质的结合性降低,中膜弹性纤维、胶原纤维被消化,增生活跃的细胞向内膜的迁移性增高。迁移至内膜的平滑肌细胞呈高增殖性。     

淋病奈瑟氏菌中国流行株gyrA和parC基因与喹诺酮类耐药性的相关性

目的　调查中国地区淋病奈瑟氏菌 (NG)对喹诺酮类的耐药性状况 ,探讨高水平耐药的基因突变株对喹诺酮类耐药机制的作用 .方法　对 9a来临床分离保存淋球菌流行株进行了体外环丙沙星 (CIP)药敏实验 .筛选出 76株高水平CIP耐药株 ,通过 PCR扩增了其中的 1 8株 NG的 gyr A和par C喹诺酮耐药决定区基因 ,并对扩增子直接测序 .通过N he I酶切、脉冲电场凝胶电泳 (PFEG)分析了这些菌株的遗传关系 .结果　环丙沙星的耐药检出率有逐年增高的趋势 ,MIC≥ 1 .0 mg· L- 1的菌株由 1 993年的 5 .1 %上升到 2 0 0 1年的 2 1 .4% .对照组中的 1 8株敏感菌只有两株发生了 gyr A的单一突变 ,未发现 par C变异 ;而耐药组中 89% (1 6 )菌株的gyr A发生了 Ser- 91向 Phe的单一突变株或 (和 ) par C的双突变 .88.9% (1 5 )的菌株的 gyr A发生了 Ser- 91向 Phe和 Asp-95向 Gly的突变 .在发生 par C突变中 72 %属于 Asp- 86向Asn突变 .PFEG分析发现 1 0株具有完全一致的 gyr A和par C突变模式 .同时也发现来自不同地区的菌株的 PFEG指纹图是不同的 .结论　研究表明 ,在中国 NG流行株对喹诺酮类耐药率呈增长趋势 ;NG流行株对喹诺酮产生耐药性与gyr A和 par C基因双重突变有着密切的关系     

HPLC-ELSD及紫外分光光度法测定三七中皂苷的含量

采用反相高效液相色谱蒸发激光散射检测器测定三七中人参皂苷Rg1的含量。色谱柱为CLC-ODS(6．0mm×150mm),流动相为乙腈-水(3070),蒸发激光散射检测器。定量方法简单,准确。回收率为100．50％,RSD为1．82％。并用紫外分光光度法测定了三七中总皂苷的含量,结果和HPLC法基本一致,说明该方法定量准确,回收率为101．50％,RSD为1．44％。结论认为两方法均可以控制三七的质量。     

Partial Sequence Analysis of the Genome of Human Herpesvirus 7 YY5 Isolated from Saliva Samples

Ｈｕｍａｎｈｅｒｐｅｓｖｉｒｕｓ 7(ＨＨＶ 7)ｉｓｏｎｅｏｆｔｈｅｍｏｓｔｒｅｃｅｎｔｌｙｄｉｓｃｏｖｅｒｅｄｍｅｍｂｅｒｏｆｔｈｅｈｅｒ ｐｅｓｖｉｒｕｓｆａｍｉｌｙ .Ｉｔｗａｓｆｉｒｓｔｉｓｏｌａｔｅｄｆｒｏｍａｃｔｉｖａｔ ｅｄＣＤ4 Ｔｃｅｌｌｓｆｒｏｍｐｅｒｉｐｈｅｒａｌｂｌｏｏｄｍｏｎｏｎｕ ｃｌｅａｒｃｅｌｌｓ (ＰＢＭＣｓ)ｏｆａｈｅａｌｔｈｙｉｎｄｉｖｉｄｕａｌ[1] ,ａｐａｔｉｅｎｔｗｉｔｈｃｈｒｏｎｉｃｆａｔｉｇｕｅｓｙｎｄｒｏｍｅ(ＣＦＳ) [2 ] ,ａｎｄｆｒｏｍｓａｌｉｖａｏｆｈｅａｌ…     

QTcd、JTcd在运动试验中的意义

为了解QTcd、JTcd在心电图活动平板运动试验结果判断中的价值 ,对 10 0例活动平板运动试验阳性者及 80例阴性者运动前后的心电图QTcd、JTcd进行对比观察。结果表明 :运动前两组QTcd、JTcd差异均无显著性 ( P〉0 .0 5 ) ;运动后 2min运动试验阳性组与阴性组比较 ,QTcd、JTcd差异有高度显著性 (P <0 .0 1) ;阳性组运动试验后 2minQTcd、JTcd均较运动前显著延长 ( P <0 .0 1) ;阴性组运动后 2minQTcd、JTcd与运动前比较差异无显著性 ( P >0 .0 5 )。认为运动试验后QTcd、JTcd延长可作为判断运动试验结果的指标。     

Subchronic Toxicity of 3,3',4,4',5-Pentachlorobiphenyl in the Rat: I. Clinical, Biochemical, Hematological, and Histopathological Changes

The systemic, toxicity of 3,3',4,4',5-pentachlorobiphenyl (PCB126) following subchronic dietary exposure was investigatedin Sprague-Dawley rats. PCB 126 was administered to rats ofboth sexes at concentrations of 0.1, 1.0, 10, or 100 ppb intheir diet for 13 weeks. Another group of rats received a loadingdose of 5 µg PCB/kg body wt at the start of the feedingperiod followed by exposure to 10 ppb PCB diet for the sameperiod of time as the other groups. Growth suppression and decreasedfood consumption were observed in the highest dose groups ofboth sexes. Increased organ/body weight ratios for the liveroccurred in the 10 and 100 ppb groups of both sexes. Rats ofboth sexes exposed to the highest dose of the PCB also exhibitedincreased relative kidney, spleen, and brain weights. Hematologicaland most serum biochemical changes were confined to the 100ppb groups. These included elevated alkaline phosphatase, bilirubin,cholesterol, and aspartate aminotransferase, and decreased serumglucose, hemoglobin, erythrocytes, hematocrit, and platelets.A dose-dependent increase in liver ethoxyre-sorufin-O-deethylaseactivity was observed in rats of both sexes starting at 0.1ppb. A dose-dependent increase in liver uroporphyrin levelswas observed in both sexes and significant changes occurredin the female rats at 1.0 ppb and higher dose groups. Decreasedliver vitamin A was observed in the 10 ppb group and higherin both sexes. Kidney vitamin A was elevated in the 100 ppbgroup. No statistically significant changes were noted in concentrationsof brain biogenic amines. PCB 126 residues were 10-fold higherin liver than in fat. Treatment-related histopathological changeswere observed in the thymus, thyroid, bone marrow, and liverof rats exposed to the 10 ppb diet, but increased frequencyof mild changes was observed in most of these tissues at the1.0 ppb level. Based on the above data, the no adverse effectlevel was judged to be 0.1 ppb in the diet or 0.01 µg/kgbody wt/day.     

晶状体上皮细胞PAI—1蛋白酶mRNA的表达

研究从转录水平确定晶状体上皮细胞是否能够合成纤麦原激活物抑制物－１蛋白酶。方法体外培养的牛晶状体上皮细胞,当细胞生长融合后,抽提ＲＮＡ;采用Ｎｏｔｈｅｒｎｂｌｏｔ分析技术,对抽提得到的牛晶状体上皮细胞ＲＮＡ用特异的ｃＤＮＡ探针进行检测。结果在牛晶状体上皮细胞的基因转录产物中存在有ＰＡＩ－１ｍＲＮＡ的表达,所表达的ＰＡＩ－１ｍＲＮＡ碱基长度为２．３ｋｂ。结论牛晶状体上皮细胞能够分泌ＰＡＩ－１蛋白酶：