Nano-Graphene Layer from Facile, Scalable and Eco-Friendly Liquid Phase Exfoliation Strategy as Effective Barrier Layer for High-Performance and Durable Direct Liquid Alcohol Fuel Cells.

Graphene, in spite of exceptional physio-chemical properties, still faces great limitations in its use and industrial scale-up as highly selective membranes (enhanced ratio of proton conductivity to fuel cross-over) in liquid alcohol fuel cells (LAFCs), due to complexity and high cost of prevailing production methods. To resolve these issues, a facile, low-cost and eco-friendly approach of liquid phase exfoliation (bath sonication) of graphite to obtain graphene and spray depositing the prepared graphene flakes, above anode catalyst layer (near the membrane in the membrane electrode assembly (MEA)) as barrier layer at different weight percentages relative to the base membrane Nafion 115 was utilized in this work. The 5 wt.% nano-graphene layer raises 1 M methanol/oxygen fuel cell power density by 38% to 91 mW·cm-2, compared to standard membrane electrode assembly (MEA) performance of 63 mW·cm-2, owing to less methanol crossover with mild decrease in proton conductivity, showing negligible voltage decays over 20 h of operation at 50 mA·cm-2. Overall, this work opens three prominent favorable prospects: exploring the usage of nano-materials prepared by liquid phase exfoliation approach, their effective usage in ion-transport membrane region of MEA and enhancing fuel cell power performance.

Prevalences of levofloxacin resistance and pncA mutation in isoniazid-resistant Mycobacterium tuberculosis in Hong Kong.

INTRODUCTION: In 2018, the World Health Organization recommended a 6-month treatment regimen that included levofloxacin and pyrazinamide for isoniazid-resistant Mycobacterium tuberculosis without rifampicin resistance (Hr-TB). Susceptibility testing for both drugs is not routinely performed for Hr-TB in Hong Kong. This study examined the prevalences of levofloxacin and pyrazinamide resistances in Hr-TB and explored associated risk factors. METHODS: All Hr-TB isolates archived during 2018 were retrieved. Isolates were de-duplicated to identify unique cases. Levofloxacin susceptibility testing was performed using the MGIT 960 System; pncA gene sequencing was used as a surrogate indicator of pyrazinamide susceptibility. Previous laboratory records for each case were analysed. RESULTS: In total, 160 phenotypic Hr-TB cases were identified from among 3411 patients with tuberculosis (4.7%). Among these, 157 were analysed, revealing 0.6% (n=1) levofloxacin resistance and 4.5% (n=7) pyrazinamide resistance, respectively. Independent risk factors associated with pncA mutations included history of tuberculosis in the affected patient and isoniazid poly-resistance (ie, double and triple resistances), but not mono-resistance. CONCLUSION: For Hr-TB in Hong Kong, levofloxacin resistance is rare and pyrazinamide resistance-associated pncA mutations are uncommon. Routine susceptibility testing for these drugs is not indicated unless related risk factors are identified.

Molecular detection of Mycoplasma genitalium in endocervical swabs and associated rates of macrolide and fluoroquinolone resistance in Hong Kong.

INTRODUCTION: There is a global trend of increasing macrolide and fluoroquinolone resistance in Mycoplasma genitalium (MG), such that international guidelines recommend molecular detection of resistance if a patient has MG-positive test results. Tests for MG are not routinely performed in Hong Kong. This study examined the detection of MG in endocervical swabs and the associated macrolide and fluoroquinolone resistance rates. METHODS: Endocervical swabs received from two sexual health clinics in Hong Kong for routine assessments of Chlamydia trachomatis and Neisseria gonorrhoeae were also subjected to detection of MG. All MG-positive samples were tested for resistance-mediating mutations in 23S rRNA, parC, and gyrA genes. Laboratory records and past results for each patient were analysed. RESULTS: In total, endocervical swabs from 285 patients were included in this study. Mycoplasma genitalium was detected in swabs from 21 patients (7.4%) by real-time polymerase chain reaction with a commercial kit. Among MG-positive samples which were successfully analysed further, macrolide resistance-mediating mutations in 23S rRNA were found in 42.1% (8/19); fluoroquinolone resistance-related mutations in parC and gyrA were found in 65% (13/20) and 0% (0/20), respectively. All macrolide-resistant MG strains were also fluoroquinolone-resistant (42.1%, 8/19). No assessed factors were associated with the detection of MG or resistance-related mutations. CONCLUSION: In Hong Kong, MG was detected in endocervical swabs from 7.4% of patients in sexual health clinics, with high rates of macrolide and fluoroquinolone resistance. These findings warrant careful review of testing, clinical correlation, and treatment strategies for MG in the context of increasing antibiotic resistance.

Uncertainty Quantification for Flow and Transport in Highly Heterogeneous Porous Media Based on Simultaneous Stochastic Model Dimensionality Reduction.

Groundwater flow models are usually subject to uncertainty as a consequence of the random representation of the conductivity field. In this paper, we use a Gaussian process model based on the simultaneous dimension reduction in the conductivity input and flow field output spaces in order quantify the uncertainty in a model describing the flow of an incompressible liquid in a random heterogeneous porous medium. We show how to significantly reduce the dimensionality of the high-dimensional input and output spaces while retaining the qualitative features of the original model, and secondly how to build a surrogate model for solving the reduced-order stochastic model. A Monte Carlo uncertainty analysis on the full-order model is used for validation of the surrogate model.

Membrane-less organic-inorganic aqueous flow batteries with improved cell potential.

A membrane-less organic-inorganic flow battery based on zinc and quinone species is proposed. By virtue of the slow dissolution rate of the deposited anode (<11.5 mg h-1 cm-2), the battery has a cell voltage of ca. 1.52 V with an average energy efficiency of ca. 73% at 30 mA cm-2 over 12 cycles.

groEL encodes a highly antigenic protein in Burkholderia pseudomallei.

No recombinant protein is available for serodiagnosis of melioidosis. In this study, we report the cloning of the groEL gene, which encodes an immunogenic protein of Burkholderia pseudomallei. Bidirectional DNA sequencing of groEL revealed that the gene contained a single open reading frame encoding 546 amino acid residues with a predicted molecular mass of 57.1 kDa. Basic Local Alignment Search Tool analysis showed that the putative protein encoded by groEL is homologous to the chaperonins encoded by the groEL genes of other bacteria. It has 98% amino acid identity with the GroEL of Burkholderia cepacia, 98% amino acid identity with the GroEL of Burkholderia vietnamiensis, and 82% amino acid identity with the GroEL of Bordetella pertussis. Furthermore, it was observed that patients with melioidosis develop a strong antibody response against GroEL, suggesting that the recombinant protein and its monoclonal antibody may be useful for serodiagnosis in patients with melioidosis and that the protein may represent a good cell surface target for host humoral immunity. Further studies in these directions would be warranted.

Identification by 16S ribosomal RNA gene sequencing of an Enterobacteriaceae species from a bone marrow transplant recipient.

AIMS: To ascertain the clinical relevance of a strain of Enterobacteriaceae isolated from the stool of a bone marrow transplant recipient with diarrhoea. The isolate could not be identified to the genus level by conventional phenotypic methods and required 16S ribosomal RNA (rRNA) gene sequencing for full identification. METHODS: The isolate was investigated phenotypically by standard biochemical methods using conventional biochemical tests and two commercially available systems, the Vitek (GNI+) and API (20E) systems. Genotypically, the 16S bacterial rRNA gene was amplified by the polymerase chain reaction (PCR) and sequenced. The sequence of the PCR product was compared with known 16S rRNA gene sequences in the GenBank database by multiple sequence alignment. RESULTS: Conventional biochemical tests did not reveal a pattern resembling any known member of the Enterobacteriaceae family. The isolate was identified as Salmonella arizonae (73%) and Escherichia coli (76%) by the Vitek (GNI+) and API (20E) systems, respectively. 16S rRNA sequencing showed that there was only one base difference between the isolate and E coli K-12, but 48 and 47 base differences between the isolate and S typhimurium (NCTC 8391) and S typhi (St111), respectively, showing that it was an E coli strain. The patient did not require any specific treatment and the diarrhoea subsided spontaneously. CONCLUSIONS: 16S rRNA gene sequencing was useful in ascertaining the clinical relevance of the strain of Enterobacteriaceae isolated from the stool of the bone marrow transplant recipient with diarrhoea.

Multicultural mental health services.

Oregon has a significant Indochinese minority community. Seen through the eyes of this group, few of the difficulties minorities encounter when seeking culturally competent services have changed under the Oregon Health Plan.

A comparative study of family functioning among Vietnamese and Cambodian refugees.

This study was designed to determine the extent of family problems among a clinic population of Cambodian and Vietnamese refugees, and to identify similarities and differences between the two groups. All 107 patients with adolescent children from a total clinic population of 298 were interviewed using a semistructured questionnaire, results were tabulated, and statistical methods were applied. The types of problems with children described by parents were classified into the dimensions of communication, personal behaviors, school performance, social behaviors, and antisocial behaviors. There were significantly more problems described by Vietnamese parents as compared with Cambodian parents. Vietnamese parents reported significantly more dissatisfaction with life in the United States. For both ethnic groups, parents' relationships with their adolescent children were a major source of concern and had a major impact on parents' perceptions of their own health. Yet, there were important ethnic differences between these refugee groups in how patients perceived their problems.

A prospective study of the natural course of alcoholism in a Native American village.

This study examines the natural course of alcoholism in a Native American village. We found that the remission rates of alcoholism were quite similar despite the different methods used: life histories (SADS-L interview) showed a 63% remission rate; a 19-year follow-up prospective showed 60% in remission; and following a cohort of all those who developed alcoholism in the village over the previous 19 years revealed a 60.9% remission rate. The data also showed vast differences in drinking problems between men and women. In the span of 19 years, the differences of point prevalence rates of alcoholism between men and women have jumped from that of two times (52% vs 26%) to five times (36.4% vs 7%). Furthermore, the results showed women had a higher rate of alcohol abuse (8.4% vs 3.6%) and a far higher remission rate (82% vs 52%) when compared to men. Three-fourths of the men in the studied sample had a lifetime history of alcohol dependence. They usually began drinking in their teens and developed dependency by their early twenties. About half stopped after an average of 15 years of drinking. The majority (83%) of the subjects who stopped drinking did so spontaneously or for specific personal-related reasons rather than because they received alcohol treatment.

Indochinese patients in the civil commitment process.

This paper examines in detail the involvement of a group of Indochinese patients in the Oregon Civil Commitment process in the calendar years of 1985 and 1986. The authors found that there was no apparent difference in the rate of commitment as contrasted to the overall commitment rate of the general population. The results also indicated that there was heavy reliance on the Indochinese Psychiatric Program and staff to divert the involuntary Indochinese patients out of the commitment process. Furthermore, comparing the involuntary Indochinese patients to a randomly selected cohort of Indochinese patients hospitalized in the same period revealed no differences in demographic data, diagnosis, and treatment history except that the involuntary group was significantly younger and predominantly male. Finally, the follow-up study of the two cohorts showed high rates of hospitalization, noncompliance, and treatment drop-out.

Improving quality assurance through psychiatric mortality and morbidity conferences in a university hospital.

To make quality assurance more outcome oriented, the department of psychiatry in a university hospital developed a program of psychiatric mortality and morbidity conferences for reviewing cases with undesirable outcomes. The conference combines aspects of a traditional medical mortality and morbidity conference with features of utilization review and risk management. Case review is focused on mortality, morbidity, or specific indicators developed by the departmental services involved and on a determination of whether an adverse outcome was avoidable, possibly avoidable, or unavoidable. The authors summarize the 100 cases reviewed in the first seven months. They believe the focus on outcome gives the method a useful role in quality assurance; advantages include its recognizable contributions to continuing education and training.

The natural history of medical and psychiatric disorders in an American Indian community.

In 1969, a Pacific Northwest American Indian community cohort (n = 100) was interviewed for the presence of physical and psychiatric illnesses. The same community was studied again in 1988. This study describes the outcome among the original 100 subjects. The schedule for Affective Disorders and Schizophrenia Lifetime Version (SADS-L) served as the basic interview instrument, supplemented by data from medical records, death certificates, and medical and community informants. Twenty-five subjects had died, 13 from cardiovascular disorders and seven from alcohol-related illnesses. Among the 46 subjects re-interviewed, hypertension, heart disease, and diabetes had become significant sources of medical morbidity. Alcoholism was the most significant cause of psychiatric morbidity, particularly among males. This study indicates that greater attention should be focused upon prevention and treatment of alcoholism, cardiovascular disorders, and diabetes in this community and in other American Indian populations.

Psychiatric epidemiology of an Indian village. A 19-year replication study.

This 1988 study reports the point and lifetime prevalence of psychiatric disorders, using DSM-III-R criteria, of a sample (approximately 25%) of adult members of an Indian village previously studied in 1969. The basic instrument was the Schedule for Affective Disorders and Schizophrenia, augmented by available medical information and administered by experienced psychiatrists. Subjects were interviewed and results were weighed for the age- and sex-distributed population. The results indicated a high point prevalence of alcohol dependence (32.8%), with a lifetime prevalence of 72.8%, among males. The lifetime prevalence of affective disorders among women was also high (36.8%), but less so among men (19.3%). When compared with the DSM-III-R diagnoses of the 1969 study, the point prevalence rates of alcohol dependence and abuse disorders fell from 39% to 21%. Also, fewer subjects were judged to be psychiatrically impaired. Even though the prevalence of psychiatric disorders was lower in the current study, the rates for alcohol disorders and affective disorders were still far higher than those reported in Epidemiologic Catchment Area studies. Alcohol dependence (especially among young men) and affective disorder (among women) were major problems.

The prevalence of posttraumatic stress disorder and its clinical significance among Southeast Asian refugees.

All 322 patients at a psychiatric clinic for Indochinese refugees were surveyed to determine the presence of posttraumatic stress disorder (PTSD). If PTSD was not diagnosed at the time of initial evaluation, a structured reinterview was performed. Seventy percent of the patients (N = 226) met the criteria for a current diagnosis of PTSD, and an additional 5% (N = 15) met the criteria for a past diagnosis. The Mein had the highest rate of PTSD (93%) and the Vietnamese the lowest (54%). Of the patients with PTSD who were enrolled in the clinic before March 1988, 46% (N = 87) were given a diagnosis of PTSD only after the reinterview. PTSD is a common disorder among Indochinese refugees, but the diagnosis is often difficult to make.

Recurrent cementifying fibroma.

A case of recurrent cementifying fibroma in an adolescent girl, necessitating repeated surgery, is reported. The multifocal nature of the tumor in the third recurrence, seven years after the initial surgery, leads to speculation as to the possible multifocal development of cementifying fibroma. Histologic assessment is of no value in predicting the behavior of this tumor, but radical surgery does not appear to be justified, even for tumors that have recurred. In the present case, however, partial mandibulectomy was ultimately performed, because, despite repeated conservative surgery, the patient had recurrences that caused pain and gross deformity.

Spin label and biochemical studies of erythrocyte membranes in Alzheimer's disease.

Electron spin resonance, enzymatic, and SDS-polyacrylamide gel electrophoretic investigations of erythrocyte membranes from patients with Alzheimer's disease were performed. Alterations in the physical state of membrane proteins in Alzheimer's disease erythrocytes were found by spin labeling studies. However, no alterations in membrane lipid fluidity or in the activities of membrane-bound sodium plus potassium-stimulated, magnesium-dependent adenosine triphosphatase or acetylcholinesterase could be demonstrated. Also, no changes in staining profiles of AD erythrocyte membrane proteins subjected to electrophoresis were observed. The altered conformation and/or organization of extraneural membrane proteins in Alzheimer's disease suggests the possibility that this disorder may have more widespread membrane involvement than was originally thought.

Evidence for an altered physical state of membrane proteins in erythrocytes in Friedreich's ataxia.

Electron spin resonance, scanning electron microscopic, and SDS-polyacrylamide gel electrophoretic studies of erythrocytes in Friedreich's ataxia have been performed. No alteration in the physical state of membrane lipids, in morphology, or in the staining profile of erythrocytes in Friedreich's ataxia could be demonstrated. An altered conformation and/or organization of proteins in erythrocyte membranes in this disorder was suggested by spin labeling studies (P less than 0.025), favoring the possibility of a generalized membrane abnormality in Friedreich's ataxia. These findings are discussed in relation to other inherited neurological diseases where similar studies have been performed.

Irreversibility of obstructive changes in severe asthma in childhood.

The findings in three children with severe asthma are presented. Following intensive round-the-clock therapy with theophylline (the dosage of which maintained serum levels of theophylline between 10 microgram/ml and 20 microgram/ml) and therapy with prednisone (20 mg twice daily for three weeks or more), there were improvements in spirometric and body plethysmographic measurements. Despite this therapy, abnormalities in the forced expiratory volume in one second, the maximal midexpiratory flow, the residual volume, and specific airway conductance remained. These cases represent a subgroup of asthmatic children with reactive airways who have an irreversible component to their disease.