铸铁和镀铬水龙头对过夜自来水水质的影响

[目的]探讨水龙头等涉水管件对生活饮用水水质的影响，为避免黄浊水对人体的危害，为制定生活饮用水涉水产品卫生安全标准提供科学依据。[方法]2004年在滨卅l市市区选择不同区域居室，采集铸铁水龙头和镀铬水龙头的水头水（自来水），检测铁、锌、锰、铜、铅、六价铬含量及色度、浑浊度。[结果]2种水龙头的水头水的色度、浑浊度均高于中段水；2种水龙头水头水和中段水中锰、铜、铅、六价铬含量的差异无统计学意义；2种水龙头水头水的铁、锌含量分别高于中段水；2种水龙头过夜水头水中铁、锌含量均与出水量呈负相关关系。[结论]水龙头的材质影响水头水中色度、浑浊度及铁、锌含量，建议使用卫生安全的供水管材和水龙头。     

中药喷雾干燥粉末的沸腾制粒工艺

目的优选中药喷雾干燥粉末中不加辅料沸腾制粒的工艺条件,达到有效地减小中药服用剂量的目的。方法分别以中药水煎及大孔吸附树脂纯化浸膏的喷雾干燥粉末为制粒原料,用水、乙醇及其浸膏为粘合剂,采用沸腾制粒技术制粒。以粉末的成型性、颗粒质量及生产效率选择黏合剂;以进、出风温度及喷液速度对颗粒质量稳定性的影响,确立工艺条件。结果水煎液喷雾干燥粉末成型性能差,乙醇浓度达85%时,可制得较好颗粒;大孔吸附树脂纯化的中药浸膏喷雾干燥粉末可制得质量好的颗粒,尤以水为黏合剂制粒的生产效率高、成本低,制得的颗粒性状好、质量稳定。结论水煎浓缩液喷雾干燥粉末易吸潮,黏性重,不加辅料难以制粒;大孔树脂纯化的中药浸膏喷雾干燥粉末不易吸湿,成型性能佳;以水为黏合剂沸腾制粒工艺简单,易于操作,适合工业大生产的要求。     

新型胆碱酯酶抑制剂对AD大鼠空间记忆及海马结构胆碱能纤维的影响

目的探讨新型胆碱酯酶抑制剂(NAI)及水迷宫训练对AD大鼠海马结构胆碱能纤维的影响。方法用36只Wistar♂大鼠制作AD动物模型,随机分成3组:NAI组、石杉碱甲组(Hup组)、单纯损伤组(SO组)。水迷宫训练后,采用组织化学方法测定海马结构胆碱能纤维密度。结果①定位航行实验中,NAI组逃避潜伏期较SO组显著缩短(P<0.01)。②空间探索实验中,NAI组跨越各象限平台相应位置次数占总次数百分率较SO组明显增高(P<0.01)。③组化结果显示:NAI组海马结构胆碱能纤维密度较SO组明显增加(P<0.05)。尽管NAI组胆碱能纤维密度高于Hup组,但无统计学意义。结论经NAI治疗及水迷宫行为训练后的AD大鼠,海马结构内胆碱能纤维密度明显增加,提示NAI及水迷宫训练联合作用可促进AD大鼠海马结构胆碱能纤维重建。     

妇科调经颗粒水提取工艺的探讨

目的:确定妇科调经颗粒水提取的最佳工艺条件.方法:用正交试验等方法,以芍药苷的含量为考核指标,对溶剂水的用量、提取时间、提取次数等影响提取的因素进行考察,进行考核.结果:最佳工艺条件为:用10倍和8倍量的水煎煮2次,第1次3 h,第2次2 h.结论:用最佳组合参数能充分、有效地提取药材中水溶性的有效成分.     

水质及水温对消毒清洗液浓度的影响

目的探讨消毒清洗液受水质及水温影响而导致浓度降低、消毒效果减弱的原因及对策. 方法分别做两组实验:蒸馏水组:室温下采用蒸馏水和自来水分别配制2%消毒清洗液20杯,定时观察沉淀生成和浓度变化;自来水组:用10～60℃的自来水做溶剂,每隔10℃为一组,每组5杯,静置观察1 h沉淀生成和浓度变化. 结果蒸馏水配制的消毒清洗液无沉淀,自来水配制的消毒清洗液虽有少量沉淀,但不影响消毒液浓度和消毒效果;随着水温的增高,沉淀物逐渐增加,温度＞40℃,浓度≤0.05%,低于消毒要求. 结论水质对消毒液浓度影响不大,不影响消毒效果,水温＞40℃时,影响消毒液浓度,建议应用蒸馏水或＜40℃的自来水配制消毒清洗液.     

湖北钉螺在非适宜地东平湖生存繁殖的纵向观察

目的在南水北调条件下,观察人工北移至非适宜地区山东省东平湖区湖北钉螺生存繁殖的能力。方法近年,在东平湖区的湖心岛以螺笼放养钉螺,定量观察其生存繁殖情况。结果亲代钉螺可以在东平湖越冬生存,存活率为60.51%(118/195);经过2个冬季24个月放养,繁殖产生了子2代钉螺228只,其螺口数量较亲代钉螺数量增长了14.00%;经过3个冬季36个月放养,钉螺繁殖产生了子3代钉螺86只,其数量较亲代钉螺减少了57.00%,与子2代钉螺数量比较减少了62.28%;经过4个冬季48个月放养,钉螺存活率为0。结论南水北调东线南端长江取水口地区的湖北钉螺在血吸虫病非流行区山东省东平湖区可以繁殖到子3代,生存繁殖的时间不超过4个冬季、48个月,呈现逐年消亡趋势。报道了在中国大陆北纬35 055/地区,人工北移到此地的钉螺在湖滩铁丝笼内放养状态下生存繁殖的纵向观察结果。     

Regulation of environmental chemicals

Dibromochloropropane (1,2-dibromo-3-chloropropane, DBCP), a pesticide used widely for over 20 years to control nematodes on crops, turf and in nurseries, was banned by the United States Environmental Protection Agency (US EPA) in 1977 because of evidence of infertility in men and induction of a variety of tumors in laboratory animals. Despite the ban on the use of DBCP, this pesticide remains persistent in soil and continues to be detected as a groundwater contaminant in areas of past high use, in particular California's Central Valley. In this review, we present a critical evaluation of the available scientific literature on the potential for DBCP to affect cancer risk, including the results of animal cancer bioassays, human epidemiological studies and in vitro and in vivo genotoxicity studies. In addition, we provide updated information on DBCP chemistry and metabolism, production and past use, current regulations, its environmental fate, potential for human exposure and current remediation efforts. Results from long-term cancer bioassays in rodents show a statistically significant increase in the incidence of malignant and benign mammary gland tumors in female rats treated orally with DBCP compared to controls and some evidence of increased incidence of mammary fibroadenomas in DBCP low-dose treated female rats exposed by inhalation. Significantly increased incidence of tumors of the forestomach occurred in both sexes of rats and mice treated orally. Rats exposed to DBCP by inhalation showed significant increases in tumors of the tunica vaginalis in males; tumors of the pharynx and adrenal gland in females; and tumors of the tongue, nasal turbinate and nasal cavity in both sexes compared to controls. Male and female mice exposed to DBCP by inhalation experienced increased tumor incidence in the lungs and nasal cavity compared to controls. Significant increases in tumors of the lung and forestomach have also been reported in female mice treated by a dermal route. Although high mortality rates in both rat and mouse bioassays limited the ability to detect tumors late in life, the induction of a variety of tumors by multiple routes of exposure in two rodent species provides clear evidence of a DBCP tumorigenic response. In vitro, in vivo and human genotoxicity studies indicate that DBCP is capable of acting as a mutagen and clastogen. Few studies have been conducted to assess whether DBCP workplace or drinking water exposures affect cancer risk in humans. While case-control, cohort and ecological epidemiology studies have not found significant, positive associations between DBCP exposure and cancer in exposed populations, these studies have numerous limitations including small numbers of participants, a lack of control for confounding factors, lack of exposure information on DBCP and other chemicals and short follow-up times. Given the persistent nature of DBCP contamination in areas of past use, efforts should be made to continue remediation efforts and follow previously exposed populations for development of certain human cancers, including breast, ovarian, stomach, respiratory, oral and nasal cancers, among others.     

Sodium and water intake are not affected by GABAC receptor activation in the lateral parabrachial nucleus of sodium-depleted rats

The activation of GABAergic receptors, GABA_A and GABA_B, in the lateral parabrachial nucleus (LPBN) increases water and sodium intake in satiated and fluid-depleted rats. The present study investigated the presence of the GABA_C receptor in the LPBN, its involvement in water and sodium intake, and its effects on cardiovascular parameters during the acute fluid depletion induced by furosemide combined with captopril (Furo/Cap). One group of male Wistar rats (290–300 g) with bilateral stainless steel LPBN cannulas was used to test the effects of a GABA_C receptor agonist and antagonist on the fluid intake and cardiovascular parameters. We investigated the effects of bilateral LPBN injections of trans-4-aminocrotonic acid (TACA) on the intake of water and 0.3 M NaCl induced by acute fluid depletion (subcutaneous injection of Furo/Cap). c-Fos expression increased (P<0.05), suggesting LPBN neuronal activation. The injection of different doses of TACA (0.5, 2.0 and 160 nmol) in the LPBN did not change the sodium or water intake in Furo/Cap-treated rats (P > 0.05). Treatment with the GABA_C receptor antagonist (Z)-3-[(aminoiminomethyl)thio]prop-2-enoic acid sulfate (ZAPA, 10 nmol) or with ZAPA (10 nmol) plus TACA (160 nmol) did not change the sodium or water intake compared with that for vehicle (saline) (P > 0.05). Bilateral injections of the GABA_C agonist in the LPBN of Furo/Cap-treated rats did not affect the mean arterial pressure (MAP) or heart rate (HR). The GABA_C receptor expression in the LPBN was confirmed by the presence of a 50 kDa band. Although LPBN neurons might express GABA_C receptors, their activation produced no change in water and sodium intake or in the cardiovascular parameters in the acute fluid depletion rats. Therefore, the GABA_C receptors in the LPBN might not interfere with fluid and blood pressure regulation.     

Effects of trophic 2,2′, 4,4′-tetrabromodiphenyl ether (BDE-47) exposure in Oreochromis niloticus: A multiple biomarkers analysis

Polybrominated diphenyl esters are emerging environmental contaminants with few toxicological data, being a concern for the scientific community. This study evaluated the effects of BDE-47 on the health of Oreochromis niloticus fish. The animals were exposed to three doses of BDE-47 (0, 0.253, 2.53, 25.3 ng g⁻¹) every 10 days, for 80 days. The BDE-47 affected the hepatosomatic and gonadosomatic index in female and the condition factor by intermediate dose in both sexes. The levels of estradiol decreased and the T4 are increased, but the vitellogenin production was not modulated in male individuals. Changes in AChE, GST, LPO and histopathology were observed while the integrated biomarker response index suggests that the lowest dose of BDE-47 compromised the activity of antioxidant enzymes. The oral exposure to BDE-47 in environmental concentrations is toxic to O. niloticus and the use of multiple biomarkers is an attribution in ecotoxicology studies and biomonitoring programs.