检索结果-南通市图书馆

Degradation and fate of 2,4-dinitroanisole(DNAN)and its intermediates treated with Mg/Cu bimetal:Surface examination with XAS,DFT,and LDI-MS

引用

Journal of Environmental Sciences 2023年第7期129卷 161-173页

作者： Andrew Mai Emese Hadnagy Qiantao Shi lotanna ezeonu Jason P.Robbins Simon G.Podkolzin Agamemnon Koutsospyros Christos Christodoulatos Center for Environmental Systems Stevens Institute of TechnologyHobokenNJ 07030USA School of Engineering and Technology University of Washington TacomaTacomaWA 98402USA

A novel Mg-based bimetal reagent(Mg/Cu)was used as an enhanced reductive system to degrade insensitivemunition 2,4-dinitroanisole(DNAN),a contaminant found in energeticladenwaste.Degradation ofDNANwas significantly impacted by dissolved oxygen and studied in anoxic and oxic bimetal systems(i.e.,purging with N2,air,or O_(2) gas).Degradation occurred through sequential nitroreduction:first one nitro group was reduced(ortho or para)to form short-lived intermediates 2-amino-4-nitroanisole or 4-amino-2-nitroanisole(2-ANAN or 4-ANAN),and then subsequent reduction of the other nitro group formed 2,4-diaminoanisole(DAAN).The nitro-amino intermediates demonstrated regioselective reduction in the ortho position to 2-ANAN;Regioselectivity was also impacted by the anoxic/oxic environment.Under O_(2)-purging DNAN degradation rate was slightly enhanced,but most notably O_(2) significantly accelerated DAAN generation.DAAN also further degraded only in the oxygenated Mg/Cu system.Adsorption of DNAN byproducts to the reagent occurred regardless of anoxic/oxic condition,resulting in a partition of carbon mass between the adsorbed phase(27%-35%)and dissolved phase(59%-72%).Additional surface techniqueswere applied to investigate contaminant interaction with Cu.Density functional theory(DFT)calculations identified preferential adsorption structures for DNAN on Cu with binding through two O atoms of one or both nitro groups.X-ray absorption spectroscopy(XAS)measurements determined the oxidation state of catalyticmetal Cu and formation of a Cu-O-N bond during treatment.Laser desorption ionization mass spectrometry(LDI-MS)measurements also identified intermediate 2-ANAN adsorbed to the bimetal surface.

关键词： Insensitive munition Magnesium bimetal Reductive degradation Adsorption Surface analysis DFT DNAN Oxic

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Comparative Skin Histology of Frogs Reveals High-elevation Adaptation of the Tibetan Nanorana parkeri

引用

Asian Herpetological Research 2019年第2期10卷 79-85页

作者： Chunhua YANG Tingting FU Xinqiang LAN Yun ZHANG lotanna Micah NNEJI Robert W.MURPHY Yanbo SUN Jing CHE State Key Laboratory of Genetic Resources and Evolution Kunming Institute of ZoologyChinese Academy of Sciences650223 KunmingChina Institute of Physical Science and Information Technology Anhui University230601 HefeiChina Kunming College of Life Science University of Chinese Academy of SciencesKunming 650204China Key Laboratory of Animal Models and Human Disease Mechanisms The Chinese Academy of Sciences and Yunnan ProvinceKunming Institute of ZoologyChinese Academy of Sciences650223 KunmingChina Centre for Biodiversity and Conservation Biology Royal Ontario Museum100 Queen’s ParkTorontoOnt.M5S 2C6Canada Center for Excellence in Animal Evolution and Genetics Chinese Academy of Sciences650223 KunmingChina

Adaptations to extreme environmental conditions are intriguing. Animal skin, which directly interacts with external environment, plays diverse and important roles in adaptive evolution. The thin and bare skin of amphibians is sensitive to external environmental conditions and, thus, it facilitates investigations into adaptations for living in extreme environments. Herein, we compare the structures of skin in four anuran species living at elevations ranging from 100 m to 4500 m to assess phenotypic innovations in the skin of Nanorana parkeri, which lives at extremely high elevations. Analyses reveal similar basic skin structures, but N. parkeri differs from the other species by having more epidermal capillaries and granular glands, which correlate highly with responses to hypoxia and/or ultraviolet(UV) radiation. Further intraspecific comparisons from frogs taken at ~4500 m and ~2900 m reveal that all of the changes are fixed. Changes occurring only in the higher elevation population, such as possessing more skin pigments, may represent local adaptations to coldness and/or UV radiation. These results provide a morphological basis for understanding further the molecular adaptations of these frogs.

关键词： Nanorana parkeri skin structure phenotypic innovation high-elevation adaptation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Growth indices of seeds(maize and cowpea)grown in heavy metal contaminated soil treated with ginger extract

引用

Toxicology Advances 2023年第4期5卷 15-23页

作者： Tatah Verwiyeh Silas ezeonu Chukwuma Stephen Moses Adondua Abah Abu Sunday Michael Umaru John Isaac Roy Yohanna Emochone Faculty of Pure and Applied Sciences Federal University WukariWukariPMB 1020Taraba StateNigeria

The consumption of maize and cowpea in Africa and developing countries is high,owing to the fact that they are readily available,coupled the with nutritional benefits they provide.Growth loss has been seen in crops cultivated on heavy metal polluted soils as a consequence of alterations in physiological and biochemical processes.This study was aimed at assessing the growth indices of seeds(maize and cowpea)grown on heavy metal contaminated soil treated with ginger extracts.The study adopted a Complete Randomized Design(CRD)in which growth indices of either maize or cowpea were examined from each crop type grown on soil without any pollutant or treatment and soils with metal pollutants;with or without treatment with ginger extracts in the individual experiments.Data were analyzed using ANOVA.The results showed that ginger extract induced oxidative stress on cowpea after 10 days of cultivation with root length significantly(P≤0.05)higher on the normal control-G-M and+L-G which recorded 7.60 and 7.3 cm respectively.Patterns of growth indices noticed after 30 and 40 days of cowpea cultivation were variable showing least growth in leaf development.Highest maize root(27.00 cm),shoot(8.85 cm)and leaf(25.25 cm)development were recorded in maize grown on soil without metal contamination but treated with ginger(+G-M-positive control)after days 10,40 and 40 after cultivation.It was observed that the soil contaminated with heavy metals affected the growth pattern of the crops thereby causing stunted growth,chlorosis,discoloration and wilting.It could be concluded that cowpea performed better in shoot of both treated and untreated soils even though the values were not significantly different from that of root and leaf while maize showed a decrease in shoot even though the values for root and leaf were not significantly different.

关键词： contaminants cowpea ginger extract maize heavy metals antioxidant bioremediation

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

In vivo antiplasmodial activity of Bombax buonopozense root bark aqueous extract in mice infected by Plasmodium berghei

引用

Journal of Traditional Chinese Medicine 2017年第4期37卷 431-435页

作者： Akuodor Godwin Christian ezeonu Chinonyelum Thecla Essien Augustine Dick Asika Ebere Chile Chilaka Kingsley Chimsorom Nwachukwu Daniel Ckukwu Nwobodo Ndubuisi Nwobodo Department of Pharmacology and Therapeutics Faculty of Medicine Ebonyi State UniversityAbakaliki P.M.B. 053 Nigeria Department of Paediatrics Faculty of Medicine Ebonyi State University Abakaliki RM.B.053 Nigeria Department of Pharmacology College of Medical Sciences University of Calabar Calabar P.M.B. 1115 Nigeria Department of Pharmacology and Therapeutics College of Health Sciences Nnamdi Azikiwe University Awka P.M.B. 5025 Nigeria Department of Physiology College of Medicine University of Nigeria Enugu P.M.B. 1011 Nigeria

OBJECTIVE: To evaluate the in vivo antiplasmodial activity and the oral acute toxicity of the Bombax buonopozense root bark aqueous extract.METHODS: The in vivo antiplasmodial activity of the root bark aqueous extract of Bombax buonopozense against early and established rodent malaria infections in chloroquine sensitive Plasmodium berghei strain in mice was investigated, and oral acute toxicity of the aqueous root bark extract of Bombax buonopozense was also evaluated in mice.RESULTS: The findings of this study revealed significant(P < 0.05) and dose dependent decrease in parasitaemia in the parasitized groups treated with varying doses of the extract(50-200 mg/kg p.o.) in both suppressive and curative tests. There was also significant decrease in parasitaemia density in the chloroquine treated group. The aqueous extract was found no toxicity in mice and the oral LD50 was determined to be greater than 5000 mg/kg.CONCLUSION: Bombax buonopozense root bark aqueous extract possesses potent antiplasmodial activity and may therefore, serve as potential sources of new antimalarial agents.

关键词：寄生虫感染水提取物疟原虫根皮木棉体内小鼠急性毒性

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Prevalence and Pattern of Abnormal Pap Smear among Pregnant Women Attending Antenatal Clinic in a Missionary Hospital in Abakaliki, Southeast Nigeria

引用

Open Journal of Obstetrics and Gynecology 2018年第8期8卷 728-740页

作者： Kenneth Chinedu Ekwedigwe Paul Olisaemeka ezeonu Felix Edegbe Chidi Esike Anthony Tagbo Agbata Chukwuemeka Ikechi Ukaegbe Okechukwu Bonaventure Anozie Obiorah Godfrey Asiegbu Maradona Isikhuemen Department of Obstetric & Gynaecology Federal Teaching Hospital Abakaliki Nigeria Department of Pathology Federal Teaching Hospital Abakaliki Nigeria Department of Obstetrics & Gynaecology University of Benin Teaching Hospital Benin Nigeria

BACKGROUND: Cervical cancer is the most common type of cancer affecting the genital tract among women in developing countries. Screening programmes have been well talked about in Nigeria, but they are not well organized. Hence, the incidence of cervical cancer does not appear to be reducing. A possible way of solving this problem is by doing an opportunistic pap smear among women attending antenatal clinics, since a good number of women do access antenatal care. OBJECTIVES: To determine the prevalence, knowledge, awareness, practice, risk factors and pattern of Pap smear among women attending antenatal clinic in Mile 4 hospital, Abakaliki. METHOD: This is a cross-sectional study carried out at the antenatal clinic of Mile 4 Hospital, Abakaliki, Nigeria. A total of 110 consecutive pregnant women who fulfilled the inclusion criteria and have given their consent were recruited into the study at the time of their first prenatal (booking clinic) visit for antenatal care. Data was collected using a questionnaire. Conventional Papanicolaou smear was taken using the standard procedure. The cytopathologic findings were documented in the questionnaire. RESULTS: Out of the 110 pregnant women who had cervical cytology by Pap smear, 7 had pre-invasive cervical lesion, giving a prevalence rate of 6.3%;5 (71.4%) were low-grade squamous intraepithelial lesion (LGSIL) while 2 (28.6%) were high-grade squamous intraepithelial lesion (HGSIL). Fifty women (45.5%) had negative smears. Inflammatory smears were seen in 50 women (45.5%). Insufficient smear was seen in 3 women (2.7%). Fifty-six women had knowledge about cervical cancer (50.9%), while thirty-six women (32.7%) were aware of a screening program for cervical cancer and only 2 women (1.8%) had been screened in the past. Hence, from this study, the population screening rate was approximately 2%. The risk factors were age of coitarche years, number of sexual partners, previous history of sexual transmitted infection, genital warts, human immune deficiency virus and use of contra

关键词： Pregnancy Pap Smear Cervical Cancer

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Determinants of Cord Care Practices among Mothers in Abakaliki, Ebonyi State, South East, Nigeria

引用

Open Journal of Preventive Medicine 2019年第5期9卷 43-50页

作者： U. V. Asiegbu O. G. Asiegbu C. T. ezeonu O. B. Ezeanosike B. N. Onyire Institute of Child Health Department of Paediatrics Federal Teaching Hospital Abakaliki Nigeria Department of Obstetrics and Gynecology Federal Teaching Hospital Abakaliki Nigeria Department of Paediatrics Federal Teaching Hospital Abakaliki Nigeria

Introduction: Unhygienic cord-care practices are major public health concern because of the associated gross neonatal and infant morbidity and mortality. Various factors have been linked to these practices. This study aims to identify the determinants of cord care practices among mothers in Abakaliki, Ebonyi State, South East, Nigeria. Methods: A cross sectional questionnaire based study involving women attending antenatal clinics and those who brought their babies to the immunization clinics of Federal Teaching Hospital, Mile Four Hospital and Maternal/Child Primary Health Care Center, all in Abakaliki. Results: Two hundred and seventy three mothers participated in the study. The majority of the participants aged 26 to 35 years (60.07%), had tertiary education (49.45%) and were business women (38.46%). Mothers who had secondary and tertiary education basically applied methylated spirit (p-value 0.0014) and chlorhexidine (p-value 0.0289) as a form cord care while those who had primary or no formal education cared for cord using hot water, Vaseline, close up tooth paste and local herbs. The mothers educational status, occupation and parity also determined the care given the umbilical cord after birth. Conclusion: Cord care practices are determined and influenced by several factors in Ebonyi State. Health education and awareness campaigns should be upheld and targeted among women of child bearing age found in women meetings, local markets and primary health care delivery centers especially in the rural setting.

关键词： Determinants Cord Care Practices Mothers Abakaliki

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The Fetal Outcome and Fetal Wastage Pattern among Different Types of Obstetric Fistula at the National Obstetric Fistula Centre, Abakaliki, Nigeria

引用

Open Journal of Obstetrics and Gynecology 2020年第4期10卷 538-545页

作者： Kenneth Chinedu Ekwedigwe Onwe O. Emeka Isikhuemen E. Maradona Iwe Bobby Azubuike K. Onyebuchi Obuna Johnson ezeonu P. Olisaemeka Onoh C. Robinson Ekwedigwe P. Ifeanyi Clinical Services National Obstetric Fistula Centre Abakaliki Nigeria Department of Obstetrics and Gynaecology Alex-Ekwueme Federal University Teaching Hospital Abakaliki Nigeria Department of Paediatrics Alex-Ekwueme Federal University Teaching Hospital Abakaliki Nigeria Department of Obstetrics and Gynaecology University of Benin Teaching Hospital Benin Nigeria

BACKGROUND: Obstetric Fistula is a major public health problem in developing world. It is associated with a high fetal wastage rate. The objective of this study was to evaluate different types of obstetric fistula and their fetal wastage rate. METHOD: A retrospective population study was done at the National Obstetric Fistula Centre, Abakaliki between 1st January-31st December, 2016. The calculated minimum sample size was 3, however, the total number of 203 patients were studied. The case notes of all the women who had obstetric fistula repairs over the period were analyzed. RESULTS: The mean age from this study was 38 ± 12.1 years. The fetal wastage rate from this study was 82.76% while the live birth was 17.24%. Seventy percent of the stillbirth were delivered via SVD, while 11% of stillbirth were delivered through EmCS. Twelve different types of fistula were identified in this study using anatomical classifications. Large extensive fistula, urethral loss and multiple fistula had the highest fetal wastage of 100% respectively. This was followed by mid-vaginal fistula (95.7%), Juxtaurethral fistula 94.4%, Juxtacervical fistula 88.5%, Intracervical fistula 85.71%, Ureteric fistula 85.71%, Vesicouterine 84.21%, Vault fistula 62.5%. Rectovaginal fistula had the least fetal wastage of 15.79% and the highest live birth of 84.2%. CONCLUSION: The findings showed a high fetal wastage rate amongst women with obstetric fistula. There was high fetal wastage across different types of obstetric fistula. Rectovaginal fistula had the best outcome in terms of live births.

关键词： Obstetric Fistula Fetal Wastage/Stillbirth Live Birth

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Genetic variation and cryptic lineage diversity of the Nigerian red-headed rock agama Agama agama associate with eco-geographic zones

引用

Current Zoology 2019年第6期65卷 713-724页

作者： lotanna M.NNEJI Adeniyi C.ADEOLA Fang YAN Agboola O.OKEYOYIN Ojo C.OLADIPO Yohanna SAIDU Dinatu SAMUEL Ifeanyi C.NNEJI Akindele O.ADEYI Abiodun B.ONADEKO Temidayo E.OLAGUNJU Olatunde OMOTOSO Segun O.OLADIPO Oluyinka A.IYIOLA John Y.USONGO Timothy AUTA Abbas D.USMAN Halima ABDULLAHI Odion O.IKHIMIUKOR Wei-Wei ZHOU Jie-Qiong JIN Obih A.UGWUMBA Adiaha A.A.UGWUMBA Min-Sheng PENG Robert W.MURPHY Jing CHE State Key Laboratory of Genetic Resources and Evolution Kunming Institute of ZoologyChinese Academy of SciencesKunming 650223China Sino-Africa Joint Research Center Chinese Academy of SciencesKunming 650223China National Park Service Headquarters Federal Capital TerritoryAbuja 900001Nigeria Old Oyo National Park Oyo State 211242Nigeria Gashaka Gumti National Park SertiTaraba State 663101Nigeria Department of Biological Sciences University of AbujaFCTAbuja 902101Nigeria Department of Zoology University of IbadanIbadanOyo State 200284Nigeria Department of Zoology University of LagosLagos 100213Nigeria Department of Biosciences and Biotechnology Kwara State UniversityMaleteKwara State 241104Nigeria Department of Zoology Faculty of Life SciencesUniversity of llorinllorinKwara State 240103Nigeria Department of Zoology Modibbo Adama University of TechnologyYola 640101Nigeria Department of Biological Sciences Federal University Dutsin-MaKatsina State 821Nigeria Department of Biology Kashim Ibrahim College of EducationMaiduguriBorno State 600230Nigeria Department of Microbiology University of IbadanIbadanOyo State 200284Nigeria Centre for Biodiversity and Conservation Biology Royal Ontario MuseumTorontoOntarioCanada M5S 2C6

Nigeria is an Afrotropical region with considerable ecological heterogeneity and levels of biotic endemism.Among its vertebrate fauna,reptiles have broad distributions,thus,they constitute a compelling system for assessing the impact of ecological variation and geographic isolation on species diversification.The red-headed rock agama,Agama agama,lives in a wide range of habitats and,thus,it may show genetic structuring and diversification.Herein,we tested the hypothesis that ecology affects its genetic structure and population divergence.Bayesian inference phylogenetic analysis of a mitochondrial DNA(mtDNA)gene recovered four well-supported matrilines with strong evidence of genetic structuring consistent with eco-geographic regions.Genetic differences among populations based on the mtDNA also correlated with geographic distance. The ecologicalniche model for the matrilines had a good fit and robust performance. Population divergence alongthe environmental axes was associated with climatic conditions, and temperature ranked highestamong all environmental variables for forest specialists, while precipitation ranked highest for theforest/derived savanna, and savanna specialists. Our results cannot reject the hypothesis that nicheconservatism promotes geographic isolation of the western populations of Nigerian A. agama.Thus, ecological gradients and geographic isolation impact the genetic structure and population divergenceof the lizards. This species might be facing threats due to recent habitat fragmentation,especially in western Nigeria. Conservation actions appear necessary.

关键词： Agama agama ecological speciation genogeography Nigeria population divergence vegetation

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Awareness of Obstetric Vesicovaginal Fistula among Pregnant Women in a Rural Hospital

引用

Advances in Reproductive Sciences 2017年第3期5卷 39-46页

作者： P. O. ezeonu K. C. Ekwedigwe M. E. Isikhuemen M. O. Eliboh R. C. Onoh L. O. Lawani L. O. Ajah E. I. Dimejesi Department of Obstetrics and Gynecology Federal Teaching Hospital Abakaliki Nigeria Department of Obstetrics and Gynaecology University of Benin Teaching Hospital Benin City Edo State Nigeria National Obstetric Fistula Centre Abakaliki Nigeria

Background: Giving birth should be a period of joy, but for more than half a million women, their pregnancy and childbirth end in death while some develop vesicovaginal fistula. Vesicovaginal fistula is an abnormal communication between the bladder and the vagina leading to continuous leakage of urine through the vagina. Little is known about the perception of pregnant women about obstetric fistula and this group of women are those who are at risk of the disease. Our aim therefore was to evaluate the level of awareness of vesicovaginal fistula among pregnant women attending antenatal clinic in a rural hospital. Methodology: This was a cross sectional study conducted at Mile 4 missionary Hospital, Abakaliki, between 1st of May and 1st of July, 2017. Data was collected with the use of questionnaire. Ethical clearance was gotten from the institutions ethical committee. Results: Their mean age was 27 ± 5 years and mean parity was 2 ± 2. Awareness of vesicovaginal fistula was 57.8%. Risk factors identified for vesicovaginal fistula were prolonged obstructed labour, instrumental vaginal delivery, caesarean section and short stature. Only 80 (39.2%) believed vesicovaginal fistula could be treated. Conclusion: Awareness of vesicovaginal fistula in the study population was 57.8%. A significant number of women were not aware that vesicovaginal fistula could be treated.

关键词： Vesicovaginal Fistula Awareness Pregnancy Prolonged Obstructed Labour

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Perception of Caesarean Section among Pregnant Women in a Rural Missionary Hospital

引用

Advances in Reproductive Sciences 2017年第3期5卷 33-38页

Introduction: Caesarean section is the delivery of a foetus through an incision made on the uterus. It is useful in situations where vaginal delivery is not feasible. Women in our setting usually see it as a reproductive failure and a sign of weakness. Our aim was to evaluate the perception of caesarean section among pregnant women attending antenatal clinic in a rural missionary hospital. Methodology: This was a cross-sectional study conducted at Mile 4 missionary hospital, Abakaliki among women attending routine antenatal clinic. Information was obtained from respondents with the aid of a questionnaire. Ethical clearance was obtained for the study. Data was analysed using the Statistical Package for Social Sciences (SPSS) version 21. Results: A total of 209 pregnant women participated in this study. Their age ranged from 14 to 43 with a mean age of 27 ± 5 years. One hundred and seventy two women (82.3%) have heard of caesarean section in the past. Eighteen (8.6%) have had caesarean section in the past while 5 were not willing to undergo the procedure again. Sixty (28.7%) are not willing to undergo caesarean section even when it is indicated. Conclusion: Despite awareness of caesarean section, women do not appear to have a positive attitude towards the procedure.

关键词： Perception Caesarean Section Rural Hospital

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：