Rapid synthesis and electrical transition in p-type delafossite CuAlO₂

Highly polycrystalline and pure delafossite phase CuAlO2 powder has been synthesised within a short annealing period, shorter than most conventional processes. This is an improvement over the conventional synthesis procedures. The conventional synthesis procedure has seen CuAlO2 only formed at high annealing temperatures ≥1100 °C over long annealing time, some as long as 96 hours. In the current process, a pure phase devoid of impurities has been obtained at a reduced calcination time of 1.5 hours in an argon atmosphere at a temperature of 1150 °C. This was confirmed by XRD and SEM/EDX. High temperature DC/AC electrical measurements show a change in the conduction mechanism from mixed conductivity (ionic + p-type) in the temperature range of 375 ≥ T ≥ 25 °C to intrinsic type behavior above 375 °C. The activation energies for these two regimes are 0.27 eV and 0.08 eV respectively. This change from mixed to p-type conductivity is confirmed by spectral analysis also. Spectral analysis using the power law also revealed that conduction is of long range hopping. The use of platinum as a contact electrode at elevated temperatures has a detrimental effect on the electrical properties since it encourages the formation of CuAl2O4 at the interface due to the formation of a more stable Cu–Pt alloy by virtue of the chemical reaction Image Pt+2CuAlO2→CuAl2O4+PtCu

Laryngeal involvement causing dysphonia in a 29 year old nursing mother with lepromatous leprosy

Leprosy is a granulomatous disease that mainly affects the skin and peripheral nerves. It is caused by infection with mycobacterium leprae ormycobacterium lepromatosus. In most instances, diagnosis of leprosy can easily be made based on the clinical signs and symptoms. However, when patients present with atypical features, clinical diagnosis can be a challenge. We report a case of a nursing mother with lepromatous leprosy who presented with dysphonia and skin lesions initially thought to be a deep cutaneous mycosis

Health and healthcare access among Zambia's female prisoners: a health systems analysis.

BackgroundResearch exploring the drivers of health outcomes of women who are in prison in low- and middle-income settings is largely absent. This study aimed to identify and examine the interaction between structural, organisational and relational factors influencing Zambian women prisoners' health and healthcare access.MethodsWe conducted in-depth interviews of 23 female prisoners across four prisons, as well as 21 prison officers and health care workers. The prisoners were selected in a multi-stage sampling design with a purposive selection of prisons followed by a random sampling of cells and of female inmates within cells. Largely inductive thematic analysis was guided by the concepts of dynamic interaction and emergent behaviour, drawn from the theory of complex adaptive systems.ResultsWe identified compounding and generally negative effects on health and access to healthcare from three factors: i) systemic health resource shortfalls, ii) an implicit prioritization of male prisoners' health needs, and iii) chronic and unchecked patterns of both officer- and inmate-led victimisation. Specifically, women's access to health services was shaped by the interactions between lack of in-house clinics, privileged male prisoner access to limited transport options, and weak responsiveness by female officers to prisoner requests for healthcare. Further intensifying these interactions were prisoners' differential wealth and access to family support, and appointments of senior 'special stage' prisoners which enabled chronic victimisation of less wealthy or less powerful individuals.ConclusionsThis systems-oriented analysis revealed how Zambian women's prisoners' health and access to healthcare is influenced by weak resourcing for prisoner health, administrative biases, and a prevailing organisational and inmate culture. Findings highlight the urgent need for investment in structural improvements in health service availability but also interventions to reform the organisational culture which shapes officers' understanding and responsiveness to women prisoners' health needs

How do farmers and seed producers get information and provide feedback on varieties in the public domain: the case of common bean in eastern Zambia?

A Study conducted by the Zambia Agriculture Research Institute (ZARI) and Seed Control and Certification Institute (SCCI) with the International Center for Tropical Agriculture (CIAT)A study was conducted in 2015 to investigate the channels used by farmers and seed producers to access information on bean varieties in the Eastern Province of Zambia, particularly in Chadiza, Chipata, Lundazi and Vubwi districts. Stakeholders, key informants and a sample of 300 bean-producing households were interviewed. Two focus group discussions (FGDs) were also conducted in Chadzombe and Chiwoko Agricultural Camps to contextualize the survey responses. The 300 households produced beans under rain-fed and irrigated wetland conditions, and also grew maize (87 %) and other legumes such as groundnut (66 %) and soybean (61%). Concerning bean production, the majority of respondents (88%) grew only local varieties while 6 % grew only improved varieties, 6% grew both varieties and the remainder (less than 1 %) were unware whether their varieties of choice were local or improved

Gastric adenocarcinoma in Zambia: A case-control study of HIV, lifestyle risk factors, and biomarkers of pathogenesis

Background. Gastric cancer is a leading cause of cancer deaths worldwide but there are few data from Africa. We recently observed a trendtowards diagnosis in younger patients.Objective. To test the hypothesis that HIV might have altered risk factors for acquisition of gastric cancer, in a case-control study in theUniversity Teaching Hospital, Lusaka, Zambia.Methods. Patients (n=52) with confirmed gastric adenocarcinoma and controls (n=94) undergoing endoscopy but with no macroscopicgastric pathology. Established risk factors and HIV status were compared.Results. HIV status did not differ significantly between cases and controls (odds ratio 1.03; 95% CI 0.2 - 4.3; p=1.00) and seroprevalencein cases was similar to that of the Zambian population. Smoking, regular alcohol intake, and gastric atrophy were all associated with cancerin univariate and multivariate analysis. Helicobacter pylori serology was positive in 84% of patients studied and cytotoxin-associated gene A(cagA) serology in 66%; neither serological marker was associated with cancer. Atrophy was common in cases (57%) and controls (30%) andassociated with both smoking and alcohol use. Intestinal metaplasia was present in 17% of the controls, but was not associated with atrophy.Conclusions. HIV was not associated with gastric cancer and does not explain the apparent younger age distribution. Atrophy was commonand was not essential for the development of intestinal metaplasia, suggesting that gastric carcinogenesis in Africa does not always followthe pathway from atrophy to intestinal metaplasia to gastric carcinoma (the so-called Correa pathway)

Plasmodium Falciparum HRP2 Elisa for Analysis of Dried Blood Spot Samples in Rural Zambia

Background: Dried blood spots are commonly used for sample collection in clinical and non-clinical settings. This method is simple, and biomolecules in the samples remain stable for months at room temperature. In the field, blood samples for the study and diagnosis of malaria are often collected on dried blood spot cards, so development of a biomarker extraction and analysis method is needed. Methods: A simple extraction procedure for the malarial biomarker Plasmodium falciparum histidine-rich protein 2 (HRP2) from dried blood spots was optimized to achieve maximum extraction efficiency. This method was used to assess the stability of HRP2 in dried blood spots. Furthermore, 328 patient samples made available from rural Zambia were analysed for HRP2 using the developed method. These samples were collected at the initial administration of artemisinin-based combination therapy and at several points following treatment. Results: An average extraction efficiency of 70% HRP2 with a low picomolar detection limit was achieved. In specific storage conditions HRP2 was found to be stable in dried blood spots for at least 6 months. Analysis of patient samples showed the method to have a sensitivity of 94% and a specificity of 89% when compared with microscopy, and trends in HRP2 clearance after treatment were observed. Conclusions: The dried blood spot ELISA for HRP2 was found to be sensitive, specific and accurate. The method was effectively used to assess biomarker clearance characteristics in patient samples, which prove it to be ideal for gaining further insight into the disease and epidemiological applications

Evidence for Histidine-Rich Protein 2 Immune Complex Formation in Symptomatic Patients in Southern Zambia

Background: Rapid diagnostic tests based on histidine-rich protein 2 (HRP2) detection are the primary tools used to detect Plasmodium falciparum malaria infections. Recent conflicting reports call into question whether α-HRP2 antibodies are present in human host circulation and if resulting immune complexes could interfere with HRP2 detection on malaria RDTs. This study sought to determine the prevalence of immune-complexed HRP2 in a low-transmission region of Southern Zambia. Methods: An ELISA was used to quantify HRP2 in patient sample DBS extracts before and after heat-based immune complex dissociation. A pull-down assay reliant on proteins A, G, and L was developed and applied for IgG and IgM capture and subsequent immunoprecipitation of any HRP2 present in immune complexed form. A total of 104 patient samples were evaluated using both methods. Results: Immune-complexed HRP2 was detectable in 17% (18/104) of all samples evaluated and 70% (16/23) of HRP2-positive samples. A majority of the patients with samples containing immune-complexed HRP2 had P. falciparum infections (11/18) and were also positive for free HRP2 (16/18). For 72% (13/18) of patients with immune-complexed HRP2, less than 10% of the total HRP2 present was in immune-complexed form. For the remaining samples, a large proportion (≥ 20%) of total HRP2 was complexed with α-HRP2 antibodies. Conclusions: Endogenous α-HRP2 antibodies form immune complexes with HRP2 in the symptomatic patient population of a low-transmission area in rural Southern Zambia. For the majority of patients, the percentage of HRP2 in immune complexes is low and does not affect HRP2-based malaria diagnosis. However, for some patients, a significant portion of the total HRP2 was in immune-complexed form. Future studies investigating the prevalence and proportion of immune-complexed HRP2 in asymptomatic individuals with low HRP2 levels will be required to assess whether α-HRP2 antibodies affect HRP2 detection for this portion of the transmission reservoir

Clinical and ultrasonographic features of abdominal tuberculosis in HIV positive adults in Zambia

Background: The diagnosis of abdominal tuberculosis (TB) is difficult, especially so in health care facilities in developing countries where laparoscopy and colonoscopy are rarely available. There is little information on abdominal TB in HIV infection. We estimated the prevalence and clinical features of abdominal (excluding genitourinary) TB in HIV infected adults attending the University Teaching Hospital, Zambia. Methods: We screened 5,609 medical inpatients, and those with fever, weight loss, and clinical features suggestive of abdominal pathology were evaluated further. A clinical algorithm was used to specify definitive investigations including laparoscopy or colonoscopy, with culture of biopsies and other samples. Results: Of 140 HIV seropositive patients with these features, 31 patients underwent full evaluation and 22 (71%) had definite or probable abdominal TB. The commonest presenting abdominal features were ascites and persistent tenderness. The commonest ultrasound findings were ascites, para-aortic lymphadenopathy (over 1 cm in size), and hepatomegaly. Abdominal TB was associated with CD4 cell counts over a wide range though 76% had CD4 counts <100 cells/μL. Conclusion: The clinical manifestations of abdominal TB in our HIV-infected patients resembled the well-established pattern in HIV-uninfected adults. Patients with fever, weight loss, abdominal tenderness, abdominal lymphadenopathy, ascites and/or hepatomegaly in Zambia have a high probability of abdominal TB, irrespective of CD4 cell count. © 2009 Sinkala et al; licensee BioMed Central Ltd