检索结果-南通市图书馆

Analysis of Health Risk Due to the Presence of Radioactivity and Chemical Elements in Groundwater,Aldama Municipality,Chihuahua,Mexico

引用

Journal of Environmental Protection 2013年第11期4卷 1265-1271页

作者： Lourdes Villalba Luis Colmenero-Sujo Adan Pinales-Munguia Guadalupe Estrada-Gutierrez Hector Rubio-Arias fernando mireles-garcia Ignacio Davila-Rangel College of Engineering Autonomous University of ChihuahuaCircuito No.1Campus UniversitarioChihuahuaChih.Mexico Technology of Chihuahua Institute ChihuahuaChih.Mexico College of Animal Husbandry and Ecology Autonomous University of Chihuahua.Periferico Francisco R.AlmadaChihuahuaChih.Mexico Regional Center of Nuclear Studies Autonomous University of ZacatecasCipres 10Frac.La PenuelaZacatecasZac.Mexico

There exist potential health risks due to the presence of some elements in groundwater. This study presents measurements of gross alpha and beta activity and chemical concentrations (fluorides and nitrates) in 25 water wells in Aldama municipality, Chihuahua, Mexico. Total alpha and beta emitter analyses were performed at the Academic Unit of Nuclear Studies at the Autonomous University of Zacatecas. Radioactive elements were concentrated by total evaporation. All samples were measured with a Wallac-Oy 1411 liquid scintillate with a pulse separation option (Pulse Shape Analysis) for 6 h. Fluorine and nitrate analyses were performed at the Faculty of Engineering of the Autonomous University of Chihuahua by flow injection-hydride generation collection-atomic absorption spectrometry. Exposure levels were calculated for each well and found to exceed maximum limits allowed under Mexican law in terms of 1) gross alpha and beta activity;and 2) fluoride and nitrate concentrations. Gross alpha activity in two wells exceeded the reference value of 0.56 Bq·L-1. Fluorides and nitrates were found in 40% and 48% of water wells, respectively. Fluoride values were higher than 1.5 mg·L-1, and the exposure doses for adults and children exceeded the reference value of 0.06 mg·kg-1·d-1. Children are the most vulnerable, since their intake doses are near or above of 0.12 mg·kg-1·d-1 of the minimum level of risk for the development of skeletal fluorosis or bone fractures. On the other hand, while nitrate concentrations in water wells exceeded the drinking water limit of 10 mg·L-1, this does not represent a serious health risk, since the calculated exposure doses for adults and children are below the chronic reference level of 1.6 mg·kg-1·d-1established by the USEPA.

关键词： Dose Fluorides Nitrates Public Health Radioactivity Well Water

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

Attenuation of UV-C Solar Radiation as a Function of Altitude(0≤z≤100 km):Rayleigh Diffusion and Photo Dissociation of O_(2) Influence

引用

Atmospheric and Climate Sciences 2017年第4期7卷 540-553页

作者： Jose Luis Pinedo-Vega Carlos Rios-Martínez David Jacobo Navarro-Solis J.Ignacio Davila-Rangel fernando mireles-garcia Sonia Azucena Saucedo-Anaya Eduardo Manzanares-Acuna Valentin Badillo-Almaraz Department:UAEN Universidad Autonoma de ZacatecasZacatecasMexico

In this paper, we present an analysis of attenuation for UV-C radiation () as a function of the altitude z () by calculating the interaction ratio between the UV-C radiation and the molecular species susceptible of interact with UV-C radiation. The Rayleigh scattering spectral cross sections were calculated, the UV-C spectral cross sections of the species susceptible of interact with UV-C radiation and the UV extraterrestrial (ETR) solar spectrum were standardized with wavelength steps of 1 nm, and The International Standard Atmosphere model (ISO 1972) was adapted to calculate the molecular density. These data were utilized to calculate the photodissociation and Rayleigh scattering ratios as a function of the altitude and to determine to what measure the photodissociation and the Rayleigh diffusion were determinants of the attenuation of UV-C radiation. It became clear that the photo dissociation of O2 is the primordial mechanism of attenuation for the UV-C radiation, but the Rayleigh diffusion appears like a mechanism that encreases the photon flux, raising the performance of the O2 photodissociation. The attenuation capacities of N2O, CO2 and water vapor (H2O) over the UV-C radiation are all similar, although smaller (less than 0.6%), and this is due to their low concentration. The O3, has the theoretical greater attenuation capacity, but it is found in mid-range altitudes? (), where the residual UV-C photons has almost vanished by O2 photo dissociation or Rayleigh diffusion, so the real effect over the UV-C attenuation is minimum.

关键词： UV-C Radiation Rayleigh Scattering O_(2) Photodissociation

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

Empagliflozin reduces brain pathology in Alzheimer's disease and type 2 diabetes

引用

Neural Regeneration Research 2024年第6期19卷 1189-1190页

作者： Carmen Hierro-Bujalance Monica garcia-Alloza Division of Physiology School of MedicineUniversidad de Cadiz Instituto de Investigacion e Innovacion en Ciencias Biomedicas de la Provincia de Cadiz (INIBICA) Salus Infirmorum-Universidad de Cadiz

Alzheimer’s disease(AD) and type 2 diabetes(T2D): More than 55 million people suffer from dementia, and it is expected that over 150 million people will suffer from this disease by 2050. AD is the most common type of dementia and while aging remains the main risk factor to suffer it, previous studies have also shown that metabolic disorders, and T2D specifically, are also major contributors(Wang et al., 2012).

关键词： INHIBITORS

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Kinematics of mandibular advancement devices (MADs): Why do some MADs move the lower jaw backward during mouth opening?

引用

BIO-DESIGN AND MANUFACTURING 2024年第5期7卷 637-650页

作者： Cabrera, Juan A. Bataller, Alex Postigo, Sergio garcia, Marcos Univ Malaga Mech Engn Dept Malaga 29071 Spain

Mandibular advancement devices (MADs) are widely used treatments for obstructive sleep apnea. MADs function by advancing the lower jaw to open the upper airway. To increase patient comfort, most patients allow the mouth to be opened. However, not all systems maintain the lower jaw in a forward position during mouth opening, which results in the production of a retrusion that favors the collapse of the upper airway. Furthermore, the kinematic behavior of the mechanism formed by the mandible-device assembly depends on jaw morphology. This means that, during mouth opening, some devices cause lower jaw protrusion in some patients, but cause its retraction in others. In this study, we report the behavior of well-known devices currently on the market. To do so, we developed a kinematic model of the lower jaw device assembly. This model was validated for all devices analyzed using a high-resolution camera system. Our results show that some of the devices analyzed here did not produce the correct behavior during patient mouth opening. (sic)(sic)(sic)(sic)(sic)(sic)(sic)MADs(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)MADs(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)-(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(

关键词： Mandibular advancement devices Lower jaw kinematics Sleep apnea OBSTRUCTIVE SLEEP-APNEA ORAL APPLIANCES MECHANISM DESIGN MOTION

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

Oxidative dissolution of Cr(OH)_(3) and mixed Fe-Cr(Ⅲ)phases by aqueous Mn(Ⅲ)-pyrophosphate complex

引用

Journal of Environmental Sciences 2024年第5期139卷 105-113页

作者： Mismel Ruiz-garcia Jordan Stanberry Giovanna Ballerini Ribeiro Vasileios Anagnostopoulos Department of Chemistry University of Central FloridaOrlando FL 32816USA

The key role of manganese(Mn)in the biogeochemical cycle of trace elements has been of great interest in recent ***,the redox properties of aqueous Mn(Ⅲ)have been studied to a lesser ***(Ⅲ)is not stable in solution by ***,when complexed with inorganic ligands,it has shown potential to oxidize and reduce trace *** the present study,we are exploring the redox characteristics of the complex Mn(Ⅲ)-Pyrophosphate(Mn(Ⅲ)-PP).This complex is stable over a wide range of pH values but requires the ratio of Mn:PP to be less than 1:***,the redox reaction of chromium(Cr(Ⅲ))and Mn(Ⅲ)-PP is investigated.A solid,Cr(OH)_(3),is used as a source of Cr(Ⅲ).For this reaction,environmentally relevant parameters,such as pH,ionic strength,ratio Mn(Ⅲ)/Cr(Ⅲ),and excess of ligand,were *** showed that Mn(Ⅲ)can effectively oxidize Cr(Ⅲ)to Cr(Ⅵ),taking about 15 days for the reaction to *** reaction occurs only under acidic conditions(pH4),and with a low excess of *** initial Mn(Ⅲ)concentration decreases as the Cr(Ⅵ)is produced,and Cr(Ⅵ)can be adsorbed back into the Cr(OH)_(3)surface,limiting the mobility of this toxic *** this adsorption,significant amounts of Cr(VI)are release in the aqueous *** study shows the importance of a mobile species(Mn-PP complex)in the oxidation of Cr(Ⅲ)and the release of Cr(Ⅵ)to the environment.

关键词： Chromium Manganese Pyrophosphate complex Sorption Ionic strength Redox

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

Intense pulsed light‑based treatment for the improvement of symptoms in glaucoma patients treated with hypotensive eye drops

引用

Eye and Vision 2024年第2期10卷 12-21页

作者： Jose Maria Martinez‑de‑la‑Casa Carlos Oribio‑Quinto Almudena Milans‑del‑Bosch Pilar Perez‑garcia Laura Morales‑Fernandez Javier garcia‑Bella Jose Manuel Benitez‑del‑Castillo Julian garcia‑Feijoo David P.Pinero Ophthalmology Unit Department of Ophthalmology and ORLFaculty of MedicineHospital Clinico San-CarlosUniversidad Complutense de MadridInstituto de Investigacion Sanitaria del Hospital Clinico San-Carlos(IdISSC)28040 MadridSpain Department of Immunology Ophthalmology and ORLSchool of MedicineInstituto de Investigaciones Oftalmologicas Ramon CastroviejoUniversidad Complutense de MadridMadridSpain Department of Optics Pharmacology and AnatomyUniversity of AlicanteAlicanteSpain

Background:Ocular surface disease in glaucoma patients is a significant ocular co-morbidity that can affect 40%to 59%of these patients *** current study was aimed at evaluating the potential clinical benefit of an intense pulsed light(IPL)-based treatment in glaucomatous patients with ocular surface disease due to prolonged hypotensive eyedrop *** our knowledge,this is the first series analyzing the therapeutic effect of this treatment option in this type of ***:This non-comparative prospective case series study enrolled a total of 30 glaucoma patients ranging in age from 57 to 94 years old and treated with hypotensive eyedrops for years with dry eye *** patients received four sessions of IPL treatment using the Optima IPL system(Lumenis,Yokneam,Israel)adjusted to the official optimized Lumenis *** in symptomatology,corneal staining,conjunctival hyperemia,non-invasive break-up time(NIBUT),tear osmolarity,tear meniscus height(TMH),meiboscore and meibomian gland expressibility was analyzed after ***:Statistically significant reductions were observed after IPL treatment in the symptomatology scores measured with different questionnaires[ocular surface disease index(OSDI),standard patient evaluation of eye dryness(SPEED)and symptom assessment questionnaire in dry eye(SANDE)]as well as with the visual analogue scale(P<0.001).Mean change in OSDI was−15.0±11.3.A significant reduction was found after treatment in the corneal staining score(P<0.001).A significant reduction was found in tear film meniscus height(P=0.012),as well as in tear film osmolarity(P=0.001).A significant reduction was also found in meibomian gland expressibility(P=0.003),changing the percentage of grade 3 eyes from 44.4%before IPL to 17.2%after ***:IPL therapy combined with meibomian gland expression(MGX)seems to be an effective option to improve symptomatology in glaucomatous patients with ocular surface diseas

关键词： Glaucoma Intense pulsed light Dry eye Meibomian glands

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

Anti-methanogenic potential of seaweeds and seaweed-derived compounds in ruminant feed:current perspectives,risks and future prospects

引用

Journal of Animal Science and Biotechnology 2024年第2期15卷 463-489页

作者： Ailbhe McGurrin Julie Maguire Brijesh K.Tiwari Marco garcia-Vaquero Section of Food and Nutrition School of Agriculture and Food ScienceUniversity College DublinDublin 4BelfieldIreland TEAGASC Food Research CentreDublin 15AshtownIreland Bantry Marine Research Station Ltd BantryCo.CorkP75 AX07GearhiesIreland

With methane emissions from ruminant agriculture contributing 17%of total methane emissions worldwide,there is increasing urgency to develop strategies to reduce greenhouse gas emissions in this *** of the proposed strategies is ruminant feed intervention studies focused on the inclusion of anti-methanogenic compounds which are those capable of interacting with the rumen microbiome,reducing the capacity of ruminal microorganisms to produce ***,seaweeds have been investigated for their ability to reduce methane in ruminants in vitro and in vivo,with the greatest methane abatement reported when using the red seaweed Asparagopsis taxiformis(attributed to the bromoform content of this species).From the literature analysis in this study,levels of up to 99%reduction in ruminant methane emissions have been reported from inclusion of this seaweed in animal feed,although further in vivo and microbiome studies are required to confirm these results as other reports showed no effect on methane emission resulting from the inclusion of seaweed to basal *** review explores the current state of research aiming to integrate seaweeds as anti-methanogenic feed additives,as well as examining the specific bioactive compounds within seaweeds that are likely to be related to these *** effects of the inclusion of seaweeds on the ruminal microbiome are also reviewed,as well as the future challenges when considering the largescale inclusion of seaweeds into ruminant diets as anti-methanogenic agents.

关键词： Asparagopsis Bromoform Methanogenesis Phlorotannin Saponin Tannin

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

Charting the course to solid-state dual-ion batteries

引用

Carbon Energy 2024年第3期6卷 132-177页

作者： Habtom D.Asfaw Antonia Kotronia Nuria garcia-Araez Kristina Edström Daniel Brandell Department of Chemistry Ångström LaboratoryUppsala UniversityUppsalaSweden Department of Chemistry University of SouthamptonSouthamptonUK

An electrolyte destined for use in a dual-ion battery(DIB)must be stable at the inherently high potential required for anion intercalation in the graphite electrode,while also protecting the Al current collector from anodic dissolution.A higher salt concentration is needed in the electrolyte,in comparison to typical battery electrolytes,to maximize energy density,while ensuring acceptable ionic conductivity and operational *** recent years,studies have demonstrated that highly concentrated organic electrolytes,ionic liquids,gel polymer electrolytes(GPEs),ionogels,and water-in-salt electrolytes can potentially be used in *** can help reduce the use of solvents and thus lead to a substantial change in the Coulombic efficiency,energy density,and long-term cycle life of ***,GPEs are suited to manufacture compact DIB designs without separators by virtue of their mechanical strength and electrical *** this review,we highlight the latest advances in the application of different electrolytes in DIBs,with particular emphasis on GPEs.

关键词： anion intercalation concentrated electrolytes dual-ion battery graphite ionic liquids polymer electrolyte

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

Thermoluminescence characterization of natural and synthetic irradiated Ce-monazites

引用

Journal of Rare Earths 2024年第4期42卷 643-650页

作者： V.Correcher C.Boronat J.garcia-Guinea J.F.Benavente T.Rivera-Montalvo CIEMAT Av.Complutense 4028040MadridSpain MNCN-CSIC J.Gutierrez Abascal 228006MadridSpain Instituto Politécnico Nacional CICATA-IPNAv.Legaria 694Mexico City11500Mexico

The thermoluminescence(TL)emission of synthetic and natural Ce-monazites was characterized here to determine the potential application in the identification of microscopic defects from a qualitative point of view trying to link each TL peak to a chemical-physical *** kinetic parameters that lead the luminescence processes were calculated by means of variable heating rate and computing glow curve deconvolution methods and allow identifying three groups of components at~90,130 and 290℃(for the mineral sample)and~90,170,220,270 and 320℃(for the synthetic CePO_(4):Nd_(0.20),La_(0.25)).The main differences appreciated in these complex TL curves are mainly due to(i)the content of impurities(natural sample contains lanthanides as well as U 0.60%and Th 5.22%)and(ii)the degree of crystallinity of the samples which is directly related to the type of impurities(synthetic monazite relies only on Nd and La).The behavior of the dose response in the range of 1-8 Gy is similar for both samples;the TL intensity increases linearly as the dose increases without changes in the position of the maxima,denoting first-order kinetic luminescence *** peak could be mostly associated with structural defects(i.e.,phase transitions),chemical reactions(i.e.,Ce3+?Ce4+redox reaction,dehydration or dehydroxylation processes)or intrinsic defects(i.e.,Frenkel defects,ODCs or NBOHCs).

关键词： Thermoluminescence Kineticparameters Phosphate Ce-monazite Defects Rare earths

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

Free-standing microscale photonic lantern spatial mode(De-)multiplexer fabricated using 3D nanoprinting

引用

Light(Science & Applications) 2024年第6期13卷 1170-1185页

作者： Yoav Dana Yehudit garcia Aleksei Kukin Lauren Dallachiesa Sterenn Guerrier Nicolas K.Fontaine Dan M.Marom Institute of Applied Physics Hebrew University of JerusalemJerusalemIsrael Nokia Bell Labs 600 Mountain AveNew ProvidenceNJ07974USA

Photonic lantern(PL)spatial multiplexers show great promise for a range of applications,such as future high-capacity mode division multiplexing(MDM)optical communication networks and free-space optical *** enable efficient conversion between multiple single-mode(SM)sources and a multimode(MM)waveguide of the same *** multiplexers operate by facilitating adiabatic transitions between the SM arrayed space and the single MM ***,current fabrication methods are forcing the size of these devices to multi-millimeters,making integration with micro-scale photonic systems quite *** advent of 3D micro and nano printing techniques enables the fabrication of freestanding photonic structures with a high refractive index contrast(photopolymer-air).In this work we present the design,fabrication,and characterization of a 6-mode mixing,375µm long PL that enables the conversion between six single-mode inputs and a single six-mode *** PL was designed using a genetic algorithm based inverse design approach and fabricated directly on a 7-core fiber using a commercial two-photon polymerization-based 3D printer and a *** the waveguides exhibit high index contrast,low insertion loss(−2.6 dB),polarization dependent(−0.2 dB)and mode dependent loss(−4.4 dB)were measured.

关键词： mode enable printing

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：