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1.
Small ; 15(16): e1900690, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30913376

RESUMO

Lithium-sulfur (Li-S) batteries are highly considered as a next-generation energy storage device due to their high theoretical energy density. For practical viability, reasonable active-material loading of >4.0 mg cm-2 must be employed, at a cost to the intrinsic instability of sulfur cathodes. The incursion of lithium polysulfides (LiPS) at higher sulfur loadings results in low active material utilization and poor cell cycling capability. The use of high-surface-area hierarchical macro/mesoporous inverse opal (IOP) carbons to investigate the effects of pore volume and surface area on the electrochemical stability of high-loading, high-thickness cathodes for Li-S batteries is presented here. The IOP carbons are additionally doped with pyrrolic-type nitrogen groups (N-IOP) to act as a polar polysulfide mediator and enhance the active-material reutilization. With a high sulfur loading of 6.0 mg cm-2 , the Li-S cells assembled with IOP and N-IOP carbons are able to attain a high specific capacity of, respectively, 1242 and 1162 mA h g-1 . The N-IOP enables the Li-S cells to demonstrate good electrochemical performance over 300 cycles.

2.
Clin Infect Dis ; 58(4): 546-54, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24253244

RESUMO

GeoSentinel is a global surveillance network of travel medicine clinics that collect data from ill international travelers. Analyses have relied on proportionate morbidity calculations, but proportionate morbidity cannot estimate disease risk because healthy travelers are not included in the denominator. The authors evaluated the use of a case-control design, controlling for GeoSentinel site and date of clinic visit, to calculate a reporting odds ratio (ROR). The association between region of travel and acute gastrointestinal illness was evaluated. All analyses found that the association with acute gastrointestinal illness was greatest among those who traveled to North Africa and South-Central Asia. There was consistency in the magnitude of the ROR and proportionate morbidity ratio (PMR) in regions such as the Caribbean. However, in other regions, the matched ROR was noticeably different than the PMR. The case-control ROR may be preferred for single-disease/syndrome analytical studies using GeoSentinel surveillance data or other surveillance data.


Assuntos
Monitoramento Epidemiológico , Gastroenterite/epidemiologia , Medicina de Viagem/métodos , Viagem , Adulto , Estudos de Casos e Controles , Feminino , Geografia , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Medição de Risco , Adulto Jovem
3.
Clin Infect Dis ; 58(10): 1347-56, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24585698

RESUMO

BACKGROUND: Brazil will host the 2014 FIFA World Cup and the 2016 Olympic and Paralympic Games, events that are expected to attract hundreds of thousands of international travelers. Travelers to Brazil will encounter locally endemic infections as well as mass event-specific risks. METHODS: We describe 1586 ill returned travelers who had visited Brazil and were seen at a GeoSentinel Clinic from July 1997 through May 2013. RESULTS: The most common travel-related illnesses were dermatologic conditions (40%), diarrheal syndromes (25%), and febrile systemic illness (19%). The most common specific dermatologic diagnoses were cutaneous larva migrans, myiasis, and tungiasis. Dengue and malaria, predominantly Plasmodium vivax, were the most frequently identified specific causes of fever and the most common reasons for hospitalization after travel. Dengue fever diagnoses displayed marked seasonality, although cases were seen throughout the year. Among the 28 ill returned travelers with human immunodeficiency virus (HIV) infection, 11 had newly diagnosed asymptomatic infection and 9 had acute symptomatic HIV. CONCLUSIONS: Our analysis primarily identified infectious diseases among travelers to Brazil. Knowledge of illness in travelers returning from Brazil can assist clinicians to advise prospective travelers and guide pretravel preparation, including itinerary-tailored advice, vaccines, and chemoprophylaxis; it can also help to focus posttravel evaluation of ill returned travelers. Travelers planning to attend mass events will encounter other risks that are not captured in our surveillance network.


Assuntos
Doenças Transmissíveis/epidemiologia , Dengue/epidemiologia , Diarreia/epidemiologia , Malária/epidemiologia , Dermatopatias Parasitárias/epidemiologia , Viagem , Brasil/epidemiologia , Febre/etiologia , Humanos , Larva Migrans/epidemiologia , Malária Vivax/epidemiologia , Risco , Estações do Ano , Tungíase/epidemiologia
4.
Clin Infect Dis ; 59(10): 1401-10, 2014 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-25091309

RESUMO

BACKGROUND: Through 2 international traveler-focused surveillance networks (GeoSentinel and TropNet), we identified and investigated a large outbreak of acute muscular sarcocystosis (AMS), a rarely reported zoonosis caused by a protozoan parasite of the genus Sarcocystis, associated with travel to Tioman Island, Malaysia, during 2011-2012. METHODS: Clinicians reporting patients with suspected AMS to GeoSentinel submitted demographic, clinical, itinerary, and exposure data. We defined a probable case as travel to Tioman Island after 1 March 2011, eosinophilia (>5%), clinical or laboratory-supported myositis, and negative trichinellosis serology. Case confirmation required histologic observation of sarcocysts or isolation of Sarcocystis species DNA from muscle biopsy. RESULTS: Sixty-eight patients met the case definition (62 probable and 6 confirmed). All but 2 resided in Europe; all were tourists and traveled mostly during the summer months. The most frequent symptoms reported were myalgia (100%), fatigue (91%), fever (82%), headache (59%), and arthralgia (29%); onset clustered during 2 distinct periods: "early" during the second and "late" during the sixth week after departure from the island. Blood eosinophilia and elevated serum creatinine phosphokinase (CPK) levels were observed beginning during the fifth week after departure. Sarcocystis nesbitti DNA was recovered from 1 muscle biopsy. CONCLUSIONS: Clinicians evaluating travelers returning ill from Malaysia with myalgia, with or without fever, should consider AMS, noting the apparent biphasic aspect of the disease, the later onset of elevated CPK and eosinophilia, and the possibility for relapses. The exact source of infection among travelers to Tioman Island remains unclear but needs to be determined to prevent future illnesses.


Assuntos
Ilhas , Sarcocistose/epidemiologia , Viagem , Adolescente , Adulto , Idoso , Biópsia , Criança , Pré-Escolar , Surtos de Doenças , Eosinófilos , Feminino , Geografia , Humanos , Contagem de Leucócitos , Malásia/epidemiologia , Masculino , Pessoa de Meia-Idade , Músculos/parasitologia , Músculos/patologia , Músculos/ultraestrutura , Vigilância em Saúde Pública , Fatores de Risco , Sarcocystis/genética , Sarcocystis/isolamento & purificação , Sarcocistose/diagnóstico , Sarcocistose/transmissão , Adulto Jovem
5.
Emerg Infect Dis ; 20(4): 532-41, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24655358

RESUMO

To understand geographic variation in travel-related illness acquired in distinct African regions, we used the GeoSentinel Surveillance Network database to analyze records for 16,893 ill travelers returning from Africa over a 14-year period. Travelers to northern Africa most commonly reported gastrointestinal illnesses and dog bites. Febrile illnesses were more common in travelers returning from sub-Saharan countries. Eleven travelers died, 9 of malaria; these deaths occurred mainly among male business travelers to sub-Saharan Africa. The profile of illness varied substantially by region: malaria predominated in travelers returning from Central and Western Africa; schistosomiasis, strongyloidiasis, and dengue from Eastern and Western Africa; and loaisis from Central Africa. There were few reports of vaccine-preventable infections, HIV infection, and tuberculosis. Geographic profiling of illness acquired during travel to Africa guides targeted pretravel advice, expedites diagnosis in ill returning travelers, and may influence destination choices in tourism.


Assuntos
Doenças Transmissíveis/epidemiologia , África/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Viagem
6.
Fam Pract ; 31(6): 678-87, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25261506

RESUMO

BACKGROUND: US residents make 60 million international trips annually. Family practice providers need to be aware of travel-associated diseases affecting this growing mobile population. OBJECTIVE: To describe demographics, travel characteristics and clinical diagnoses of US residents who present ill after international travel. METHODS: Descriptive analysis of travel-associated morbidity and mortality among US travellers seeking care at 1 of the 22 US practices and clinics participating in the GeoSentinel Global Surveillance Network from January 2000 to December 2012. RESULTS: Of the 9624 ill US travellers included in the analysis, 3656 (38%) were tourist travellers, 2379 (25%) missionary/volunteer/research/aid workers (MVRA), 1580 (16%) travellers visiting friends and relatives (VFRs), 1394 (15%) business travellers and 593 (6%) student travellers. Median (interquartile range) travel duration was 20 days (10-60 days). Pre-travel advice was sought by 45%. Hospitalization was required by 7%. Compared with other groups of travellers, ill MVRA travellers returned from longer trips (median duration 61 days), while VFR travellers disproportionately required higher rates of inpatient care (24%) and less frequently had received pre-travel medical advice (20%). Illnesses of the gastrointestinal tract were the most common (58%), followed by systemic febrile illnesses (18%) and dermatologic disorders (17%). Three deaths were reported. Diagnoses varied according to the purpose of travel and region of exposure. CONCLUSIONS: Returning ill US international travellers present with a broad spectrum of travel-associated diseases. Destination and reason for travel may help primary health care providers to generate an accurate differential diagnosis for the most common disorders and for those that may be life-threatening.


Assuntos
Doenças Transmissíveis/epidemiologia , Vigilância de Evento Sentinela , Viagem/estatística & dados numéricos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Diagnóstico Diferencial , Feminino , Humanos , Lactente , Recém-Nascido , Internacionalidade , Masculino , Pessoa de Meia-Idade , Estados Unidos/epidemiologia , Adulto Jovem
7.
Inorg Chem ; 52(20): 12033-45, 2013 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-24093446

RESUMO

Luminescent homoleptic bismuth(III) complexes have been synthesized by adding several functionalized 8-hydroxyquinolate ligands to bismuth(III) chloride in a 3:1 mole ratio in either ethanol or tetrahydrofuran (THF) solvent. These complexes have been characterized by single-crystal X-ray diffraction (XRD) analysis, UV-vis spectroscopy, fluorescence spectroscopy, and density functional theory (DFT) calculations to determine their structures and photophysical properties. Reversible dimerization of the mononuclear tris(hydroxyquinolate) complexes was observed in solution and quantified using UV-vis spectroscopy. The fluorescence spectra show a blue shift for the monomer compared with homoleptic aluminum(III) hydroxyquinolate compounds. Four dimeric compounds and one monomeric isomer were characterized structurally. The bismuth(III) centers in the dimers are bridged by two oxygen atoms from the substituted hydroxyquinolate ligands. The more sterically hindered quinolate complex, tris(2-(diethoxymethyl)-8-quinolinato)bismuth, crystallizes as a monomer. The complexes all exhibit low-lying absorption and emission spectral features attributable to transitions between the HOMO (π orbital localized on the quinolate phenoxide ring) and LUMO (π* orbital localized on the quinolate pyridyl ring). Excitation and emission spectra show a concentration dependence in solution that suggests that a monomer-dimer equilibrium occurs. Electronic structure DFT calculations support trends seen in the experimental results with a HOMO-LUMO gap of 2.156 eV calculated for the monomer that is significantly larger than those for the dimers (1.772 and 1.915 eV). The close face to face approach of two quinolate rings in the dimer destabilizes the uppermost occupied quinolate π orbitals, which reduces the HOMO-LUMO gap and results in longer wavelength absorption and emission spectral features than in the monomer form.

8.
Clin Infect Dis ; 54 Suppl 5: S480-7, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22572673

RESUMO

BACKGROUND: Approximately 40% of US travelers to less developed countries experience diarrheal illness. Using data from the Foodborne Diseases Active Surveillance Network (FoodNet), we describe travel-associated enteric infections during 2004-2009, characterizing the patients, pathogens, and destinations involved. METHODS: FoodNet conducts active surveillance at 10 US sites for laboratory-confirmed infections with 9 pathogens transmitted commonly through food. Travel-associated infections are infections diagnosed in the United States but likely acquired abroad based on a pathogen-specific time window between return from international travel to diagnosis. We compare the demographic, clinical, and exposure-related characteristics of travelers with those of nontravelers and estimate the risk of travel-associated infections by destination, using US Department of Commerce data. RESULTS: Of 64,039 enteric infections reported to FoodNet with information about travel, 8270 (13%) were travel associated. The pathogens identified most commonly in travelers were Campylobacter (42%), nontyphoidal Salmonella (32%), and Shigella (13%). The most common travel destinations were Mexico, India, Peru, Dominican Republic, and Jamaica. Most travel-associated infections occurred in travelers returning from Latin America and the Caribbean (LAC). Risk was greatest after travel to Africa (75.9 cases per 100,000 population), followed by Asia (22.7 cases per 100,000), and LAC (20.0 cases per 100,000). CONCLUSIONS: The Latin America and Caribbean region accounts for most travel-associated enteric infections diagnosed in the United States, although travel to Africa carries the greatest risk. Although FoodNet surveillance does not cover enterotoxigenic Escherichia coli, a common travel-associated infection, this information about other key enteric pathogens can be used by travelers and clinicians in pre- and posttravel consultations.


Assuntos
Diarreia/epidemiologia , Infecções por Enterobacteriaceae/epidemiologia , Enterobacteriaceae/isolamento & purificação , Doenças Transmitidas por Alimentos/epidemiologia , Viagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Centers for Disease Control and Prevention, U.S. , Criança , Pré-Escolar , Diarreia/microbiologia , Infecções por Enterobacteriaceae/transmissão , Exposição Ambiental , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Estados Unidos/epidemiologia , Adulto Jovem
9.
BMC Infect Dis ; 12: 386, 2012 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-23273048

RESUMO

BACKGROUND: Expatriates are a distinct population at unique risk for health problems related to their travel exposure. METHODS: We analyzed GeoSentinel data comparing ill returned expatriates with other travelers for demographics, travel characteristics, and proportionate morbidity (PM) for travel-related illness. RESULTS: Our study included 2,883 expatriates and 11,910 non-expatriates who visited GeoSentinel clinics ill after travel. Expatriates were more likely to be male, do volunteer work, be long-stay travelers (>6 months), and have sought pre-travel advice. Compared to non-expatriates, expatriates returning from Africa had higher proportionate morbidity (PM) for malaria, filariasis, schistosomiasis, and hepatitis E; expatriates from the Asia-Pacific region had higher PM for strongyloidiasis, depression, and anxiety; expatriates returning from Latin America had higher PM for mononucleosis and ingestion-related infections (giardiasis, brucellosis). Expatriates returning from all three regions had higher PM for latent TB, amebiasis, and gastrointestinal infections (other than acute diarrhea) compared to non-expatriates. When the data were stratified by travel reason, business expatriates had higher PM for febrile systemic illness (malaria and dengue) and vaccine-preventable infections (hepatitis A), and volunteer expatriates had higher PM for parasitic infections. Expatriates overall had higher adjusted odds ratios for latent TB and lower odds ratios for acute diarrhea and dermatologic illness. CONCLUSIONS: Ill returned expatriates differ from other travelers in travel characteristics and proportionate morbidity for specific diseases, based on the region of exposure and travel reason. They are more likely to present with more serious illness.


Assuntos
Doenças Transmissíveis/epidemiologia , Viagem/estatística & dados numéricos , Adulto , Idoso , Feminino , Humanos , Malária/epidemiologia , Masculino , Pessoa de Meia-Idade , Vigilância de Evento Sentinela , Adulto Jovem
10.
Clin Infect Dis ; 53(6): 523-31, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21832261

RESUMO

BACKGROUND: Mexico and Central America are important travel destinations for North American and European travelers. There is limited information on regional differences in travel related morbidity. METHODS: We describe the morbidity among 4779 ill travelers returned from Mexico and Central America who were evaluated at GeoSentinel network clinics during December 1996 to February 2010. RESULTS: The most frequent presenting syndromes included acute and chronic diarrhea, dermatologic diseases, febrile systemic illness, and respiratory disease. A higher proportion of ill travelers from the United States had acute diarrhea, compared with their Canadian and European counterparts (odds ratio, 1.9; P < .0001). During the 2009 H1N1 influenza outbreak from March 2009 through February 2010, the proportionate morbidity (PM) associated with respiratory illnesses in ill travelers increased among those returned from Mexico, compared with prior years (196.0 cases per 1000 ill returned travelers vs 53.7 cases per 1000 ill returned travelers; P < .0001); the PM remained constant in the rest of Central America (57.3 cases per 1000 ill returned travelers). We identified 50 travelers returned from Mexico and Central America who developed influenza, including infection due to 2009 H1N1 strains and influenza-like illness. The overall risk of malaria was low; only 4 cases of malaria were acquired in Mexico (PM, 2.2 cases per 1000 ill returned travelers) in 13 years, compared with 18 from Honduras (PM, 79.6 cases per 1000 ill returned travelers) and 14 from Guatemala (PM, 34.4 cases per 1000 ill returned travelers) during the same period. Plasmodium vivax malaria was the most frequent malaria diagnosis. CONCLUSIONS: Travel medicine practitioners advising and treating travelers visiting these regions should dedicate special attention to vaccine-preventable illnesses and should consider the uncommon occurrence of acute hepatitis A, leptospirosis, neurocysticercosis, acute Chagas disease, onchocerciasis, mucocutaneous leishmaniasis, neurocysticercosis, HIV, malaria, and brucellosis.


Assuntos
Dengue/epidemiologia , Diarreia/epidemiologia , Malária/epidemiologia , Viagem/estatística & dados numéricos , Adulto , América Central/epidemiologia , Distribuição de Qui-Quadrado , Estudos Transversais , Doenças Endêmicas , Feminino , Febre/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Morbidade , Infecções Respiratórias/epidemiologia , Fatores de Risco , Vigilância de Evento Sentinela , Dermatopatias/epidemiologia
11.
ACS Appl Mater Interfaces ; 11(19): 17393-17399, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-31012569

RESUMO

Lithium-sulfur batteries remain a promising next-generation renewable energy storage device due to their high theoretical energy density over the current commercial lithium-ion battery technology. However, to have any practical viability toward reaching the theoretical value, high-loading cathodes with sufficient sulfur content and specifically the effect of nonconductive binders must be investigated. We consider the limitations of conventional binders for high-loading, high-thickness cathodes by integrating a bifunctional binder with a linear polyethylene chain and maleate-capped ends. The linear polymer allows for flexibility within the high-loading cathode whereas the maleate ends improve the polysulfide trapping ability with carbon-sulfur binding. With the strong polysulfide immobilization ability due to the nucleophilic binding, the binder achieves high sulfur loadings of 12 mg cm-2 with a high sulfur content of 80 wt %. The work serves as a proof of concept for exploring the incorporation of polymeric materials into sulfur cathodes to realize practical viability.

12.
ACS Appl Mater Interfaces ; 10(27): 23122-23130, 2018 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-29932321

RESUMO

Lithium-sulfur (Li-S) batteries are attractive as sulfur offers an order of magnitude higher charge-storage capacity than the currently used insertion-compound cathodes. However, their practical viability is hampered by low electrochemical stability and efficiency, which results from severe polysulfide (LiPS) shuttling during cycling. We present here thin-layered MoS2 nanoparticles (MoS2-NPs) synthesized through a one-pot method and coated onto a commercial polymeric separator (as MoS2-NP-coated separator) as an effective LiPS mediator, facilitated by the nanodimension, polar interactions, and the better edge-binding sites of the MoS2-NPs. The resulting MoS2-NPs have an interlayer spacing of 0.55 nm and are stacked with a few layers. At a sulfur loading of 4.0 mg cm-2, the Li-S cell with a MoS2-NP-coated separator attains a peak discharge capacity of 983 mA h g-1, improving the electrochemical utilization of sulfur. The cell is able to maintain a high capacity of 525 mA h g-1 after 150 cycles at a C/5 rate. The MoS2-NPs are able to effectively anchor the LiPS species to their large S2- anions, enhancing the redox accessibility of sulfur cathodes and enabling better capacity retention.

13.
ACS Appl Mater Interfaces ; 9(24): 20318-20323, 2017 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-28589718

RESUMO

The viability of employing high-capacity sulfur cathodes in building high-energy-density lithium-sulfur batteries is limited by rapid self-discharge, short shelf life, and severe structural degradation during cell resting (static instability). Unfortunately, the static instability has largely been ignored in the literature. We present in this letter a long-term self-discharge study by quantitatively analyzing the control lithium-sulfur batteries with a conventional cathode configuration, which provides meaningful insights into the cathode failure mechanisms during resting. Utilizing the understanding obtained with the control cells, we design and present low self-discharge (LSD) lithium-sulfur batteries for investigating the long-term self-discharge effect and electrode stability.

14.
Am J Trop Med Hyg ; 96(6): 1388-1393, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28719282

RESUMO

AbstractThis prospective cohort study describes travelers' diarrhea (TD) and non-TD gastrointestinal (GI) symptoms among international travelers from the Boston area, the association of TD with traveler characteristics and dietary practices, use of prescribed antidiarrheal medications, and the impact of TD and non-TD GI symptoms on planned activities during and after travel. We included adults who received a pre-travel consultation at three Boston-area travel clinics and who completed a three-part survey: pre-travel, during travel, and post-travel (2-4 weeks after return). TD was defined as self-reported diarrhea with or without nausea/vomiting, abdominal pain, or fever. Demographic and travel characteristics were evaluated by χ2 test for categorical and Wilcoxon rank-sum test for continuous variables. Analysis of dietary practices used logistic generalized estimating equation models or logistic regression models. Of 628 travelers, 208 (33%) experienced TD and 45 (7%) experienced non-TD GI symptoms. Of 208 with TD, 128 (64%), 71 (36%), and 123 (62%) were prescribed ciprofloxacin, azithromycin, and/or loperamide before travel, respectively. Thirty-nine (36%) of 108 took ciprofloxacin, 20 (38%) of 55 took azithromycin, and 28 (28%) of 99 took loperamide during travel. Of 172 with TD during travel, 24% stopped planned activities, and 2% were hospitalized. Of 31 with non-TD GI symptoms during travel, six (13%) stopped planned activities. International travelers continue to experience diarrhea and other GI symptoms, resulting in disruption of planned activities and healthcare visits for some. Although these illnesses resulted in interruption of travel plans, a relatively small proportion took prescribed antibiotics.


Assuntos
Diarreia/epidemiologia , Disenteria/epidemiologia , Gastroenteropatias/epidemiologia , Viagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/uso terapêutico , Antidiarreicos/uso terapêutico , Azitromicina/uso terapêutico , Boston/epidemiologia , Ciprofloxacina/uso terapêutico , Diarreia/tratamento farmacológico , Disenteria/tratamento farmacológico , Feminino , Gastroenteropatias/tratamento farmacológico , Humanos , Loperamida/uso terapêutico , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Autorrelato , Adulto Jovem
15.
ACS Appl Mater Interfaces ; 8(7): 4709-17, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26824143

RESUMO

Lithium-sulfur (Li-S) cells have a strong edge to become an inexpensive, high-capacity rechargeable battery system. However, currently, several prohibitive challenges occur within the sulfur core, especially the polysulfide-diffusion problem. To address these scientific issues, we present here a boron-doped multiwalled carbon nanotube coated separator (B-CNT-coated separator). The B-CNT-coated separator creates a polysulfide trap between the pure sulfur cathode and the polymeric separator as a "polysulfide-trapping interface," stabilizing the active material and allowing the dissolved polysulfides to activate the bulk sulfur cores. Therefore, the dissolved polysulfides change from causing fast capacity fade to assisting with the activation of bulk sulfur clusters in pure sulfur cathodes. Moreover, the heteroatom-doped polysulfide-trapping interface is currently one of the missing pieces of carbon-coated separators, which might inspire further studies in its effect and battery chemistry. Li-S cells employing B-CNT-coated separators (i) exhibit improved cyclability at various cycling rates from 0.2C to 1.0C rate and (ii) attain a high capacity retention rate of 60% with a low capacity fade rate of 0.04% cycle(-1) after 500 cycles. We believe that our B-CNT-coated separator could light up a new research area for integrating heteroatom-doped carbon into the flexible, lightweight, carbon-coated separator.

16.
Am J Trop Med Hyg ; 94(1): 136-42, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26483125

RESUMO

We conducted a prospective cohort study to assess adherence to malaria chemoprophylaxis, reasons for nonadherence, and use of other personal protective measures against malaria. We included adults traveling to malaria-endemic countries who were prescribed malaria chemoprophylaxis during a pre-travel consultation at three travel clinics in the Boston area and who completed three or more surveys: pre-travel, at least one weekly during travel, and post-travel (2-4 weeks after return). Of 370 participants, 335 (91%) took malaria chemoprophylaxis at least once and reported any missed doses; 265 (79%) reported completing all doses during travel. Adherence was not affected by weekly versus daily chemoprophylaxis, travel purpose, or duration of travel. Reasons for nonadherence included forgetfulness, side effects, and not seeing mosquitoes. Main reasons for declining to take prescribed chemoprophylaxis were peer advice, low perceived risk, and not seeing mosquitoes. Of 368 travelers, 79% used insect repellent, 46% used a bed net, and 61% slept in air conditioning at least once. Because travelers may be persuaded to stop taking medication by peer pressure, not seeing mosquitoes, and adverse reactions to medications, clinicians should be prepared to address these barriers and to empower travelers with strategies to manage common side effects of antimalarial medications.


Assuntos
Antimaláricos/administração & dosagem , Antimaláricos/farmacologia , Malária/prevenção & controle , Adesão à Medicação/estatística & dados numéricos , Viagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Boston , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
17.
J Occup Environ Med ; 58(1): 76-82, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26479857

RESUMO

OBJECTIVES: The aim of the study was to understand more about pre-travel preparations and itineraries of business and occupational travelers. METHODS: De-identified data from 18 Global TravEpiNet clinics from January 2009 to December 2012 were analyzed. RESULTS: Of 23,534 travelers, 61% were non-occupational and 39% occupational. Business travelers were more likely to be men, had short times to departure and shorter trip durations, and commonly refused influenza, meningococcal, and hepatitis B vaccines. Most business travelers indicated that employers suggested the pre-travel health consultation, whereas non-occupational travelers sought consultations because of travel health concerns. CONCLUSIONS: Sub-groups of occupational travelers have characteristic profiles, with business travelers being particularly distinct. Employers play a role in encouraging business travelers to seek pre-travel consultations. Such consultations, even if scheduled immediately before travel, can identify vaccination gaps and increase coverage.


Assuntos
Comércio/estatística & dados numéricos , Atividades de Lazer , Saúde Ocupacional/estatística & dados numéricos , Viagem , Recusa do Paciente ao Tratamento/estatística & dados numéricos , Vacinas , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antimaláricos/uso terapêutico , Feminino , Humanos , Masculino , Missões Médicas/estatística & dados numéricos , Pessoa de Meia-Idade , Encaminhamento e Consulta/estatística & dados numéricos , Fatores de Tempo , Adulto Jovem
18.
Travel Med Infect Dis ; 14(6): 604-613, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27687076

RESUMO

BACKGROUND: The Boston Area Travel Medicine Network surveyed travelers on travel-related health problems. METHODS: Travelers were recruited 2009-2011 during pre-travel consultation at three clinics. The investigation included pre-travel data, weekly during-travel diaries, and a post-travel questionnaire. We analyzed demographics, trip characteristics, health problems experienced, and assessed the relationship between influenza vaccination, influenza prevention advice, and respiratory symptoms. RESULTS: Of 987 enrolled travelers, 628 (64%) completed all surveys, of which 400 (64%) reported health problems during and/or after travel; median trip duration was 12 days. Diarrhea affected the most people during travel (172) while runny/stuffy nose affected the most people after travel (95). Of those with health problems during travel, 25% stopped or altered plans; 1% were hospitalized. After travel, 21% stopped planned activities, 23% sought physician or other health advice; one traveler was hospitalized. Travelers who received influenza vaccination and influenza prevention advice had lower rates of respiratory symptoms than those that received influenza prevention advice alone (18% vs 28%, P = 0.03). CONCLUSIONS: A large proportion of Boston-area travelers reported health problems despite pre-travel consultation, resulting in inconveniences. The combination of influenza prevention advice and influenza immunization was associated with fewer respiratory symptoms than those who received influenza prevention advice alone.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Autorrelato , Viagem , Adulto , Boston , Feminino , Humanos , Imunização , Vacinas contra Influenza/administração & dosagem , Influenza Humana/prevenção & controle , Internacionalidade , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Adulto Jovem
19.
Am J Trop Med Hyg ; 93(5): 1110-1116, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26304922

RESUMO

An increasing number of immunocompromised individuals are pursuing international travel, and a better understanding of their international travel patterns and pretravel health care is needed. We evaluated the clinical features, itineraries, and pretravel health care of 486 immunocompromised international travelers seen at Global TravEpiNet sites from January 2009 to June 2012. We used bivariate analyses and logistic regressions using random intercept models to compare demographic and travel characteristics, vaccines administered, and medications prescribed for immunocompromised travelers versus 30,702 immunocompetent travelers. Immunocompromised travelers pursued itineraries that were largely similar to those of immunocompetent travelers, with nearly one-third of such travelers visiting countries with low human development indices. Biological agents, including tumor necrosis factor blockers, were commonly used immunosuppressive medications among immunocompromised travelers. A strong collaboration between travel-medicine specialists, primary care doctors, and specialist physicians is needed to prepare immunocompromised people for international travel. Incorporating routine questioning and planning regarding travel into the primary care visits of immunocompromised people may be useful.


Assuntos
Controle de Doenças Transmissíveis/métodos , Hospedeiro Imunocomprometido/imunologia , Viagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Aconselhamento , Atenção à Saúde , Demografia , Feminino , Humanos , Imunossupressores/uso terapêutico , Lactente , Masculino , Pessoa de Meia-Idade , Estados Unidos , Adulto Jovem
20.
J Travel Med ; 21(4): 266-71, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24734961

RESUMO

BACKGROUND: Yellow fever (YF), a potentially fatal mosquito-borne infection, is preventable with a live-attenuated vaccine, rarely associated with severe adverse events. We surveyed travelers to assess their reasons for pre-travel medical consultation, information they considered important regarding YF disease and vaccination, whether they recalled receiving this information, and whether they were involved in vaccine decision-making. METHODS: Travelers aged 18 years and older were surveyed at three Boston-area travel clinics. Only those making YF vaccination decisions were included for analyses. RESULTS: Of 831 travelers surveyed, 589 (70%) indicated making a YF vaccination decision. Travel medicine providers recommended YF vaccination to 537 (91%) of 589 travelers; 92% of these 537 received vaccine. Among 101 travelers aged 60 years and older, 9% declined the vaccine; among those younger than 60 years, 4% declined the vaccine (p = 0.06). Of 589 travelers, most agreed they needed to understand destination-specific YF risks (82%) and vaccine risks (88%), and were involved in YF vaccine decisions (87%). Less than half recalled discussing their concerns about YF vaccine with the provider (42%) or what risks and benefits mattered most to them (32%). CONCLUSION: Most participants sought YF disease and vaccine risk information and wanted to be involved in decision-making; however, fewer than half recalled discussing their opinions or concerns about YF vaccine. Providers need effective risk communication skills and the ability to elicit and respond to travelers' concerns to help them make informed, shared decisions.


Assuntos
Educação em Saúde/métodos , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Padrões de Prática Médica/estatística & dados numéricos , Viagem , Vacina contra Febre Amarela/administração & dosagem , Febre Amarela/prevenção & controle , Adulto , Idoso , Atitude do Pessoal de Saúde , Boston/epidemiologia , Participação da Comunidade/estatística & dados numéricos , Tomada de Decisões , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Medição de Risco , Medicina de Viagem , Vacinação , Adulto Jovem
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