Digging up bulk band dispersion buried under a passivation layer

Atomically controlled crystal growth of thin films has established foundations of nanotechnology aimed at the development of advanced functional devices. Crystallization under non-equilibrium conditions allows engineering of new materials with their atomically-flat interfaces in the heterostructures exhibiting novel physical properties. From a fundamental point of view, knowledge of the electronic structures of thin films and their interfaces is indispensable to understand the origins of their functionality which further evolves into realistic device application. In view of extreme surface sensitivity of the conventional vacuum-ultraviolet (VUV) angle-resolved photoemission spectroscopy (ARPES), with a probing depth of several angstroms, experiments on thin films have to use sophisticated in-situ sample transfer systems to avoid surface contamination. In this Letter, we put forward a method to circumvent these difficulties using soft X-ray (SX) ARPES. A GaAs:Be thin film in our samples was protected by an amorphous As layer with an thickness of $\sim 1$ nm exceeding the probing depth of the VUV photoemission with photon energy $h\nu$ around 100 eV. The increase of the probing depth with increasing $h\nu$ towards the SX region has clearly exposed the bulk band dispersion without any surface treatment. Any contributions from potential interface states between the thin film and the amorphous capping layer has been below the detection limit. Our results demonstrate that SX-ARPES enables the observation of coherent three-dimensional band dispersion of buried heterostructure layers through an amorphous capping layer, breaking through the necessity of surface cleaning of thin film samples. Thereby, this opens new frontiers in diagnostics of authentic momentum-resolved electronic structure of protected thin-film heterostructures.Comment: 5 pages, 3 figure

A Rapid Assessment of the Quality of Neonatal Healthcare in Kilimanjaro Region, Northeast Tanzania.

While child mortality is declining in Africa there has been no evidence of a comparable reduction in neonatal mortality. The quality of inpatient neonatal care is likely a contributing factor but data from resource limited settings are few. The objective of this study was to assess the quality of neonatal care in the district hospitals of the Kilimanjaro region of Tanzania. Clinical records were reviewed for ill or premature neonates admitted to 13 inpatient health facilities in the Kilimanjaro region; staffing and equipment levels were also assessed. Among the 82 neonates reviewed, key health information was missing from a substantial proportion of records: on maternal antenatal cards, blood group was recorded for 52 (63.4%) mothers, Rhesus (Rh) factor for 39 (47.6%), VDRL for 59 (71.9%) and HIV status for 77 (93.1%). From neonatal clinical records, heart rate was recorded for3 (3.7%) neonates, respiratory rate in 14, (17.1%) and temperature in 33 (40.2%). None of 13 facilities had a functioning premature unit despite calculated gestational age <36 weeks in 45.6% of evaluated neonates. Intravenous fluids and oxygen were available in 9 out of 13 of facilities, while antibiotics and essential basic equipment were available in more than two thirds. Medication dosing errors were common; under-dosage for ampicillin, gentamicin and cloxacillin was found in 44.0%, 37.9% and 50% of cases, respectively, while over-dosage was found in 20.0%, 24.2% and 19.9%, respectively. Physician or assistant physician staffing levels by the WHO indicator levels (WISN) were generally low. Key aspects of neonatal care were found to be poorly documented or incorrectly implemented in this appraisal of neonatal care in Kilimanjaro. Efforts towards quality assurance and enhanced motivation of staff may improve outcomes for this vulnerable group

Verbal autopsy completion rate and factors associated with undetermined cause of death in a rural resource-poor setting of Tanzania

UNLABELLED\ud \ud ABSTRACT:\ud \ud BACKGROUND\ud \ud Verbal autopsy (VA) is a widely used tool to assign probable cause of death in areas with inadequate vital registration systems. Its uses in priority setting and health planning are well documented in sub-Saharan Africa (SSA) and Asia. However, there is a lack of data related to VA processing and completion rates in assigning causes of death in a community. There is also a lack of data on factors associated with undetermined causes of death documented in SSA. There is a need for such information for understanding the gaps in VA processing and better estimating disease burden.\ud \ud OBJECTIVE\ud \ud The study's intent was to determine the completion rate of VA and factors associated with assigning undetermined causes of death in rural Tanzania.\ud \ud METHODS\ud \ud A database of deaths reported from the Ifakara Health and Demographic Surveillance System from 2002 to 2007 was used. Completion rates were determined at the following stages of processing: 1) death identified; 2) VA interviews conducted; 3) VA forms submitted to physicians; 4) coding and assigning of cause of death. Logistic regression was used to determine factors associated with deaths coded as "undetermined."\ud \ud RESULTS\ud \ud The completion rate of VA after identification of death and the VA interview ranged from 83% in 2002 and 89% in 2007. Ninety-four percent of deaths submitted to physicians were assigned a specific cause, with 31% of the causes coded as undetermined. Neonates and child deaths that occurred outside health facilities were associated with a high rate of undetermined classification (33%, odds ratio [OR] = 1.33, 95% confidence interval [CI] (1.05, 1.67), p = 0.016). Respondents reporting high education levels were less likely to be associated with deaths that were classified as undetermined (24%, OR = 0.76, 95% CI (0.60, -0.96), p = 0.023). Being a child of the deceased compared to a partner (husband or wife) was more likely to be associated with undetermined cause of death classification (OR = 1.35, 95% CI (1.04, 1.75), p = 0.023).\ud \ud CONCLUSION\ud \ud Every year, there is a high completion rate of VA in the initial stages of processing; however, a number of VAs are lost during the processing. Most of the losses occur at the final step, physicians' determination of cause of death. The type of respondent and place of death had a significant effect on final determination of the plausible cause of death. The finding provides some insight into the factors affecting full coverage of verbal autopsy diagnosis and the limitations of causes of death based on VA in SSA. Although physician review is the most commonly used method in ascertaining probable cause of death, we suggest further work needs to be done to address the challenges faced by physicians in interpreting VA forms. There is need for an alternative to or improvement of the methods of physician review

Causes of Perinatal Death at a Tertiary Care Hospital in Northern Tanzania 2000-2010: A Registry Based Study.

Perinatal mortality reflects maternal health as well as antenatal, intrapartum and newborn care, and is an important health indicator. This study aimed at classifying causes of perinatal death in order to identify categories of potentially preventable deaths. We studied a total of 1958 stillbirths and early neonatal deaths above 500 g between July 2000 and October 2010 registered in the Medical Birth Registry and neonatal registry at Kilimanjaro Christian Medical Centre (KCMC) in Northern Tanzania. The deaths were classified according to the Neonatal and Intrauterine deaths Classification according to Etiology (NICE). Overall perinatal mortality was 57.7/1000 (1958 out of 33 929), of which 1219 (35.9/1000) were stillbirths and 739 (21.8/1000) were early neonatal deaths. Major causes of perinatal mortality were unexplained asphyxia (n=425, 12.5/1000), obstetric complications (n=303, 8.9/1000), maternal disease (n=287, 8.5/1000), unexplained antepartum stillbirths after 37 weeks of gestation (n= 219, 6.5/1000), and unexplained antepartum stillbirths before 37 weeks of gestation (n=184, 5.4/1000). Obstructed/prolonged labour was the leading condition (251/303, 82.8%) among the obstetric complications. Preeclampsia/eclampsia was the leading cause (253/287, 88.2%) among the maternal conditions. When we excluded women who were referred for delivery at KCMC due to medical reasons (19.1% of all births and 36.0% of all deaths), perinatal mortality was reduced to 45.6/1000. This reduction was mainly due to fewer deaths from obstetric complications (from 8.9 to 2.1/1000) and maternal conditions (from 8.5 to 5.5/1000). The distribution of causes of death in this population suggests a great potential for prevention. Early identification of mothers at risk of pregnancy complications through antenatal care screening, teaching pregnant women to recognize signs of pregnancy complications, timely access to obstetric care, monitoring of labour for fetal distress, and proper newborn resuscitation may reduce some of the categories of deaths

VERBAL AUTOPSY IN ESTABLISHING CAUSE OF PERINATAL DEATH

Introduction: Perinatal mortality is a sensitive indicator of health status of a community andis also highly amenable to intervention. The causes of perinatal deaths in developingcountries are often difficult to establish. Verbal autopsy has been used in several countriesfor children and adults, but seldom for perinatal cause.Objective: To establish the cause of perinatal deaths using verbal autopsy.Design: Community-based cross-sectional, retrospective study to identify perinatal deathover a one year period from July 1996-June 1997. Comparison was made with hospitalrecords. An algorithm of signs and symptoms was used by trained personnel to identify thecause of perinatal death. The duration of collection of data was six months (August 1996-January 1997).Setting: Hai district of Kilimanjaro region in Tanzania.Subjects: All perinatal deaths within one year.Results: The perinatal mortality was 58 per 1000 (121 deaths and 2088 live births). Verbalautopsy could establish the cause of death in 105 of the 121 deaths. Hospital records showed79 deaths indicating that 42 deaths probably occurred at home. Among the 79 availablehospital records, the cause of death could be established in only 30 (38%). The causes ofpostnatal death were compared between the verbal autopsy and hospital records. There wasa good correlation between the same, however only 18 records were available from hospitalamong the total 31 postnatal deaths. The specificity of determining cause of death usingverbal autopsy was 100% and sensitivity 61%.Conclusion: The commonest causes of perinatal deaths were related to obstetric care,therefore interventions to curb perinatal mortality should be directed to improvement ofobstetric care. Verbal autopsy is a simpler and more sensitive tool in establishing the causeof perinatal death than hospital records in a rural district of Tanzania. Large-scale studiesare needed to validate this

Verbal autopsy in establishing cause of perinatal death

Introduction: Perinatal mortality is a sensitive indicator of health status of a community and is also highly amenable to intervention. The causes of perinatal deaths in developing countries are often difficult to establish. Verbal autopsy has been used in several countries for children and adults, but seldom for perinatal cause. Objective: To establish the cause of perinatal deaths using verbal autopsy. Design: Community-based cross-sectional, retrospective study to identify perinatal death over a one year period from July 1996-June 1997. Comparison was made with hospital records. An algorithm of signs and symptoms was used by trained personnel to identify the cause of perinatal death. The duration of collection of data was six months (August 1996- January 1997). Setting: Hai district of Kilimanjaro region in Tanzania. Subjects: All perinatal deaths within one year. Results: The perinatal mortality was 58 per 1000 (121 deaths and 2088 live births). Verbal autopsy could establish the cause of death in 105 of the 121 deaths. Hospital records showed 79 deaths indicating that 42 deaths probably occurred at home. Among the 79 available hospital records, the cause of death could be established in only 30 (38%). The causes of postnatal death were compared between the verbal autopsy and hospital records. There was a good correlation between the same, however only 18 records were available from hospital among the total 31 postnatal deaths. The specificity of determining cause of death using verbal autopsy was 100% and sensitivity 61%. Conclusion: The commonest causes of perinatal deaths were related to obstetric care, therefore interventions to curb perinatal mortality should be directed to improvement of obstetric care. Verbal autopsy is a simpler and more sensitive tool in establishing the cause of perinatal death than hospital records in a rural district of Tanzania. Large-scale studies are needed to validate this. (East African Medical Journal: 2002 79(2): 82-84

Ethnic differences in serum pepsinogen levels among Japanese and non-Japanese Brazilian gastric cancer patients and controls

A low level of serum pepsinogen I (Pg I) is a risk factor for gastric cancer (GC); low levels of Pg I and the pepsinogen ratio (Pg I:Pg II) are correlated with chronic atrophic gastritis. We report serum Pg levels and compare the degree of association with GC among Japanese and non-Japanese Brazilians. Sera were cross-sectionally ascertained from 93 Japanese Brazilian patients category matched by age and sex with 110 controls, and 228 non-Japanese Brazilian patients individually matched by age and sex with one control. Among non-Japanese Brazilians, GC was associated with a Pg I level &lt;30 ng/ml (odds ratio [OR], 2.5; 95% confidence interval [CI], 1.7-3.8) and a Pg I:Pg II ratio &lt; 3.0 (OR, 3.4; 95% CI, 2.2-5.3). However, among Japanese Brazilians, the association was present with a level of Pg I &lt; 30 ng/ml (OR, 3.5; 95% CI, 1.9-6.3), and was weak with a Pg I:Pg II ratio &lt; 3.0 (OR, 1.3; 95% CI, 0.73-2.4). Serum Pg I may be preferred to the Pg I:Pg II ratio to study the association between Pg and GC among Japanese Brazilians