Are we winning the war against posttraumatic stress disorder?

The most methodologically rigorous epidemiological study on American military personnel deployed to Iraq and Afghanistan found that 4.3% of troops developed posttraumatic stress disorder (PTSD). Among deployed combatants, 7.6% developed PTSD, whereas 1.4% of deployed noncombatants did so. The U.S. Department of Veterans Affairs has launched a program ensuring that all veterans with PTSD will receive evidence-based cognitive-behavioral therapy, and the Army has developed Battlemind postdeployment early interventions that reduce risk for the disorder.     

食品添加剂Na2 SO3对小鼠嗜多染红细胞微核率的影响

[目的]了解经口进入机体的亚硫酸盐对哺乳动物的毒性效应。[方法]以92只7～12周龄的健康昆明种小鼠为试材, 采用灌胃染毒法进行剂量效应关系和时间效应关系的微核试验。[结果] Na2SO3能诱发小鼠骨髓嗜多染红细胞微核,且随剂量增高微核率明显增加（P＜0.01）。时间效应关系的微核试验表明,Na2SO3染毒后不同时间处死动物并制片,骨髓嗜多染红细胞微核率不同,染毒后12 h的微核率与阴性对照组相比有极显著差异（P＜0.01）,随染毒后时间的延长,细胞微核率增加,24 h达到高峰,与相邻各组差异极显著（P＜0.01）,之后随时间延长而降低,表明Na2SO3诱发小鼠骨髓嗜多染红细胞微核有一定时间效应关系。[结论] 亚硫酸盐是哺乳动物染色体断裂剂和基因毒性因子。     

Respiratory exposure to lead: epidemiological and experimental dose-response relationships

Epidemiologic studies of blood lead levels in general and occupational groups show a logarithmic regression on estimated atmospheric exposure. Experimental results at the same and higher levels show a dose-response relationship which fits the same regression. The data imply that long-term increases in atmospheric lead will result in predictably higher blood lead levels in the exposed populations.     

皂素废水对蚕豆根尖细胞微核率和幼苗干重的影响

用蚕豆根尖细胞微核试验技术,对皂素废水的污染毒性进行了分析研究。结果表明,皂素废水在较高浓度条件下,能够引起较高的微核率,满足一定的线性关系,呈剂量—反应关系(r=0.97,P<0.05);试验结果表明,低浓度的皂素废水能够刺激蚕豆幼芽生长发育。     

Quantifying denitrification and its effect on ozone recovery

Upper Atmosphere Research Satellite observations indicate that extensive denitrification without significant dehydration currently occurs only in the Antarctic during mid to late June. The fact that denitrification occurs in a relatively warm month in the Antarctic raises concern about the likelihood of its occurrence and associated effects on ozone recovery in a colder and possibly more humid future Arctic lower stratosphere. Polar stratospheric cloud lifetimes required for Arctic denitrification to occur in the future are presented and contrasted against the current Antarctic cloud lifetimes. Model calculations show that widespread severe denitrification could enhance future Arctic ozone loss by up to 30%.     

Yellow fever vaccination, avian leukosis virus, and cancer risk in man

Comparison was made between 2659 veterans who died of cancer, during 1950 to 1954 or 1959 to 1963, and matched controls, based on the frequency of yellow fever immunization during World War II. The vaccine was produced from chick embryos that almost certainly contained avian leukosis-sarcoma viruses. Among the veterans, no relation was found between vaccination and leukemia, lymphoma, or other cancer.     

培育高产转Bt基因抗虫杂交棉的选择指数分析

对转Bt基因抗虫杂交棉皮棉产量的选择指数进行了分析。结果表明，由皮棉产量、衣分、单铃重，8．20蕾铃受害率组成的30号选择指数与由皮棉产量、衣分、单株铃数、单铃重、8．20蕾铃受害率组成的31号选择指数具有很大的遗传进度，分别比仅有棉产量选择的效率提高19．510％和20．780％。衣分、单株铃数、单铃重、8．20蕾铃受害率单独对皮棉产量的增产作用不大，但与皮棉产量组成选择指数时，能较大地提高遗传进度和选择效率。     

PFOS对小油菜生长发育的毒性效应及机制

为探讨全氟辛烷磺酸(PFOS)对小油菜的毒性效应,采用室内盆栽种植的方法,研究了PFOS对小油菜发芽和生长发育的影响,并结合土壤酶活性变化探讨了其毒性机理。结果表明:PFOS暴露浓度与小油菜的发芽率和茎叶增长率表现为非单调剂量-效应关系。50 mg·kg~(-1)暴露时小油菜发芽和茎叶的增长率分别为9.24%(P=0.001)和47.97%(P0.001);小油菜发芽和茎叶生长的抑制浓度分别为100 mg·kg~(-1)和250 mg·kg~(-1);随着暴露进一步增大,小油菜发芽和茎叶增长的抑制率无显著变化。土壤蔗糖酶和碱性蛋白酶活性在PFOS暴露下也表现为低浓度刺激表达、高浓度抑制表达效应,这与PFOS暴露下小油菜的生长规律具有一定的正相关性。因此,PFOS对小油菜的毒性不仅与其对小油菜的直接损伤有关,还与其对小油菜种植土壤肥力的影响有关。     

分蘖期受旱对水稻产量的影响

[目的]为水稻在非充分灌溉条件下获得最经济产量提供科学依据。[方法]以不受旱为对照,设水稻分蘖期分别受旱10、20、30、35、40 d,研究分蘖期受旱对水稻产量的影响。[结果]对照的平均产量最高,为8 100 kg/hm2,受旱10、20、30、35、40 d的平均产量分别为8 000、7 900、7 025、6 325、5 575 kg/hm2,减产率分别为1.1%、2.4%、13.1%、21.9%、31.1%。水稻在分孽期受旱20 d内不减产,20 d以上,受旱天数越长,减产越严重。[结论]水稻在分孽期受旱的减产量与受旱天数呈极显著的曲线相关关系,且受旱天数越长,减产越严重。     

抗寒锻炼期间樟子松抗寒性与生理指标的变化

抗寒锻炼期间对11年生樟子松(Pinus sylvestris L.var.mongolica Litv.)幼树枝叶进行人工低温处理,以1年生针叶和茎的相对电导率作变化曲线,结合Logistic方程计算樟子松针叶和茎的低温半致死温度(LT50),以此评价其抗寒性;并测定了针叶和茎的干物质含量及针叶最大光化学效率(Maximum photochemical efficiency of photosystem,Fv/Fm),对干物质含量和Fv/Fm与抗寒性的相关性进行分析。结果表明:①随着抗寒锻炼的进行,樟子松针叶和茎的抗寒性逐步增强,抗寒锻炼初期的9月针叶的抗寒性强于茎的抗寒性,而抗寒性达最强的3月茎的抗寒性强于针叶的抗寒性;②这些器官的干物质含量与抗寒性为多项式相关;针叶的荧光参数Fv/Fm与抗寒性为线性相关。     

Relationship between Nuclear Volumes, Chromosome Numbers, and Relative Radiosensitivities

An inverse relationship between a volume estimated to be associated with interphase chromosomes and acute lethal exposure to x-or gamma radiation has been found in 16 plant species. The apparent differences in radiosensitivities found would seem spurious, since the estimated average energy absorbed in the nucleus per chromosome (3.6 x 10(6) ev) approaches a constant (variation less than fourfold) in spite of wide ranges of lethal exposures (0.6 to 75 kr), of nuclear volumes (43 to 1758 micro(3)), and of somatic chromosome numbers (6 to 136). The regression line obtained can be used to predict the radiosensitivities of other plant species if their nuclear volumes and chromosome numbers are known.     

京白梨果实后熟软化过程中细胞壁代谢及其调控

 【目的】探讨细胞壁代谢与‘京白梨’果实软化的关系及其调控,为解决果实品质下降及迅速软化问题提供依据。【方法】用0℃、1-甲基环丙烯（1-MCP）和乙烯利处理‘京白梨’果实,测定细胞壁组分及其降解酶活性变化及调控效应。【结果】随着‘京白梨’果实后熟软化,果实细胞壁物质（CWM）、共价结合果胶（CSP）、半纤维素和纤维素含量减少,离子结合果胶（ISP）和水溶性果胶（WSP）含量增加;果胶甲酯酶（PME）和多聚半乳糖醛酸酶（PG）活性在采后3 d 后开始升高,分别在第9天和第12天出现活性高峰,α-L-阿拉伯呋喃糖苷酶（α-L-Af）和β-半乳糖苷酶（β-Gal）活性在采收时就开始升高,并持续到贮藏末期,但纤维素酶活性呈降低趋势。相关分析表明,果实硬度与半纤维素、ISP和CSP呈极显著相关,与WSP和纤维素呈显著相关;而β-Gal和α-L-Af不仅与硬度呈极显著相关,且与细胞壁组分的相关度均大于其它细胞壁降解酶,但纤维素酶未表现出相关性。0℃和1-MCP处理显著抑制了‘京白梨’果实纤维素、半纤维素与CSP含量的下降和ISP与WSP含量的增加,降低了α-L-Af、β-Gal、PME和PG活性,推迟果实软化;乙烯利的作用不大。【结论】采后‘京白梨’果实软化与细胞壁组分变化密切相关,细胞壁降解酶中,β-Gal和α-L-Af可能是果实早期软化的主要因子,PME和PG促进了果实后期软化,但纤维素酶作用不大。0℃和1-MCP能显著抑制‘京白梨’果实细胞壁代谢,延缓果实软化;乙烯利未显著促进果实软化进程。     

法桐叶烧病与树龄和光照关系及其消长动态初步调查

于2008年调查了天津城区法桐叶烧病与树龄、光照的关系及其消长动态。结果表明:法桐叶烧病发病初期在5月中旬,5月下旬到7月中旬为缓慢发病期,7月下旬直到10月底病害进入发病盛期;环境光照对病害发生轻重有显著影响,向阳面树体发病程度(平均病情指数41.66%)明显重于背阴面的树体(平均病情指数13.77%);不同树龄的树体病株率差异明显,在发病较轻的背阴面,严重度(病情指数)差异不明显,在发病严重的向阳面随树龄增加病情指数呈增长趋势。     

樟子松苗木生长规律研究

为培育根系发达、生长健壮的樟子松苗木提供依据和参考,在陕北毛乌素沙地对樟子松苗木地上、地下生长规律及其关系进行了研究。结果表明,在苗圃中1-5 a生樟子松苗木高度、生物量、地径和主根长度生长都呈现明显的节律性,苗木高度、地径随苗龄呈Logistic增长,苗木地上、地下生物量以及主根长度与苗龄呈指数函数关系;苗木地上部与地下部相比,在生物量中所占比例随苗龄增加呈上升趋势,由第1年的50.0%逐渐上升到第5年的80.0%。西北林学院学报24卷     

几种除草剂对春麦田禾本科杂草的防除效果

野燕麦、旱雀麦是青海春麦田主要的禾本科杂草,发生普遍,危害严重.为控制其危害,对目前开发出来的6种防除麦田禾本科杂草的除草剂进行了田间药效试验,结果表明:50g/L炔草酸·唑啉草脂EC 600mL/hm2、150g/L麦极WP 300g/hm、69g/L骠马EW 750mL/hm2对野燕麦的防效分别达到98.80%、9...     

新疆小花棘豆饲喂大鼠的亚慢性毒性试验及棘毒净解毒效果观察

将54只Wistar大鼠随机分为4个小花棘豆中毒组、4个解毒组（小花棘豆添加量分别为日粮的5％,10％,15％,20％）和一个间期对照组,进行为期30d的亚慢性毒性试验。试验结束,取其脏器、计算脏器系数并进行病理组织学观察。结果表明,中毒组大鼠体重显著低于对照组,下降幅度随小花棘豆添加量的增加而增大;肝肾系数增大,睾九、脾脏系数缩小,且损伤程度均随小花棘豆剂量的增加呈现明显的剂量-效应关系;病理学检查表明肝脏、肾脏等组织器官都出现不同程度的出血、充血、淋巴细胞浸润;肾脏基底膜脱落;而解毒组的睾丸系数、脾脏系数、肾脏系数与中毒组相比,均有不同程度改善．说明棘毒净对小花棘豆引起的大鼠中毒有一定保护作用。     

AVERSIVE STIMULATION OF THE RAT: LONG-TERM EFFECTS ON SUBSEQUENT BEHAVIOR

One year after exposure to intense electric shock, rats were punished with shocks of lesser intensity. The previous exposure increased the suppressive effects of the punishment during both the initial encounter with punishment and over the course of a 7-day test period. Rats that had not been previously exposed to shock recovered during continued shock punishment.     

自毒物质胁迫下不同草莓品种枯萎病抗性变化的研究

通过盆栽试验研究了17个亲本不同的草莓品种在自毒物质—对羟基苯甲酸胁迫下对枯萎病的抗性变化及其与抗病性相关生理指标的影响,采用HPLC法分析了3种抗病类型的草莓品种根系分泌物中氨基酸成分的差异。结果表明:不同抗性品种在自毒物质胁迫下发病程度均加重,病情指数上升最多的是‘红玫瑰’和‘丰香’,分别为24.44和24.86,上升幅度高达77%和69%;病情指数变化较小的为‘石莓1号’和‘土特拉’,上升幅度均小于4。对羟基苯甲酸处理使不同抗性草莓品种根系分泌物中氨基酸的含量和种类发生变化,表现为降低了对枯萎病菌"抑制型"氨基酸如天冬氨酸含量,提高了"促进型"氨基酸种类和含量。对羟基苯甲酸处理后,‘土特拉’根系分泌物中天冬氨酸含量降低了0.009mg/gDW,而‘丰香’根系分泌物中"促进型"丝氨酸含量却升高0.114mg/gDW。总之,自毒物质胁迫下根系保护酶活性和分泌氨基酸的差异可能是不同草莓品种抗枯萎病强弱的重要原因。     

LSD and genetic damage

Of nine studies in vitro, six have indicated some degree of induced chromosomal breakage after exposure to LSD; three failed to confirm these results. The damage, when found, was generally of the chromatid type, arising during or after DNA synthesis. This damage, with one exception, was the result of concentrations of drug and durations of exposure which could not be achieved in humans with reasonable dosages. There did not appear to be a dose-response relation. The magnitude of damage, when found, was in the range encompassing the effects of many commonly used substances. The absence in vitro of excretory and detoxifying systems present in vivo, as well as several negative reports, cast doubt on the relevance of in vitro results. In 21 chromosomal studies in vivo, 310 subjects were examined. Of these, 126 were treated with pure LSD; the other 184 were exposed to illicit, "alleged" LSD. A maximum of only 18 of 126 (14.29 percent) of the subjects in the group exposed to pure LSD showed higher frequency of chromosome aberration than the controls. In contrast, a maximum of 90 of 184 (48.91 percent) of the subjects taking illicit LSD showed an increase in frequency of aberrations. Of all the subjects reported to have chromosome damage, only 18 of the 108 (16.67 percent) were exposed to pure LSD. The frequency of individuals with chromosomal damage reported among illicit drug users was more than triple that associated with the use of pharmacologically pure LSD. We conclude that chromosome damage, when found, was related to the effects of drug abuse in general and not, as initially reported, to LSD alone. We believe that pure LSD ingested in moderate dosages does not produce chromosome damage detectable by available methods. No significant work on carcinogenic potential of LSD has been reported so far. No cause-and-effect relation and no increase in the incidence of neoplasia among LSD users have been demonstrated. Case reports (three in 4.0 years) of leukemia and other neoplasia in this population are rare. The results of early chromosome studies suggested that true genetic damage might be a consequence of LSD exposure. The comprehensive evidence from studies on drosophila indicates no mutagenic effect from 0.28 to 500 microg of LSD per milliliter and a definite mutagenic effect from 2,000 to 10,000 microg/ml; this is consistent with a threshold response or a sigmoid dose-effect relation. We believe that LSD is, in fact, a weak mutagen, effective only in extremely high doses; it is unlikely to be mutagenic in any concentration used by human subjects. Circular dichroism experiments suggested that the specific mechanism of action of LSD on DNA may be a direct interaction resulting in conformational changes in the DNA helix. These changes are unlikely to result in a decrease of internal stability sufficient to cause breakage of chromosomes, but they may be the physical basis of the weak mutagenicity. Early chromosomal studies implicated LSD as a potential cause of congenital malformations, fetal wastage, and germinal chromosome damage. First reports of a teratogenic effect in hamsters and rats have not been confirmed. A review of 15 rodent studies indicated a wide range of individual, strain, and species susceptibility to the effects of LSD. The applicability of such investigations to man is doubtful. In a study of human pregnancies, those exposed to illicit LSD had an elevated rate of spontaneous abortions. There is no reported instance of a malformed child born to a woman who ingested pure LSD; there are six cases of malformation associated with exposure to illicit LSD, four of which have similar limb defects. Given, however, the high frequency of unexplained "spontaneous" birth defects, the rare occurrence of malformed infants born to women who used illicit LSD may be coincidental. While there is no evidence that pure LSD is teratogenic in man, the use of any drug during pregnancy requires that its potential benefits significantly outweigh its potential hazards. From our own work and from a review of the literature, we believe that pure LSD ingested in moderate doses does not damage chromosomes in vivo, does not cause detectable genetic damage, and is not a teratogen or a carcinogen in man. Within these bounds, therefore, we suggest that, other than during pregnancy, there is no present contraindication to the continued controlled experimental use of pure LSD. Note added in proof: A brief review has been brought to our attention. Although based on a sample of only 15 studies the author reached conclusions similar to our own (92).