Surface and interfacial study of atomic layer deposited Al2O3 on MoTe2 and WTe2

The atomic layer deposition (ALD) of high-k dielectrics could build an efficient barrier against moisture and O₂ adsorption. Such a barrier is highly needed for MoTe₂ and WTe₂ transition metal dichalcogenides because of the poor structural stability and the fast oxidization in ambient air. In situ x-ray photoelectron spectroscopy and ex situ atomic force microscopy and scanning transmission electron microscopy were employed to report a comparative study between the growth of Al₂O₃ on MoTe₂ and WTe₂ by means of traditional thermal ALD and plasma-enhanced ALD (PEALD). Similar to what has been observed on other 2D materials such as MoS₂ and Graphene, the thermal ALD results in an islanding growth of Al₂O₃ on MoTe₂ due to the dearth of dangling bonds, whereas, a uniform coverage of Al₂O₃ on WTe₂ is observed and likely contributed to the high concentration of intrinsic structural defects. The PEALD behavior is consistent between MoTe₂ and WTe₂ providing a conformal and linear growth rate (∼0.08 nm/cycle), which correlates with the creation of Te-O and metal-O nucleation sites. However, a thin layer of interfacial Mo or W oxides gradually forms, resulting from the plasma-induced damage in the topmost (1-2) layers. Attempts to enhance the Al₂O₃/MoTe₂ interfacial quality by physically evaporating an Al₂O₃ seed layer are investigated as well. However, the evaporated Al₂O₃ process causes thermal damage on MoTe₂, necessitating a more 'gentle' ALD technique for the surface passivation.

Meeting the urgent need for rabies education in Haiti

The highest rate of human rabies deaths reported in the Americas is in Haiti, and most of these deaths result from rabies virus infections that occur after individuals are bitten by infected dogs and do not receive rabies post-exposure prophylaxis. One barrier to rabies prevention in Haiti is a lack of knowledge about this disease among healthcare professionals and community members. During the past 4 years, The US Centers for Disease Control and Prevention has collaborated with public health officials and partners to develop, test and refine educational materials aimed at filling this need for rabies education. This report summarizes the use of feedback from knowledge, attitudes and practises surveys; key informant interviews; and focus groups to develop culturally appropriate rabies prevention materials for community members, health officials, clinicians, laboratory professionals, veterinary professionals, government officials and national and local district leaders about ways to prevent rabies. These formative research methods were critically important in ensuring that the materials would be culturally appropriate and would stand the greatest likelihood of motivating Haitians to protect themselves from rabies. Centers for Disease Control and Prevention is using lessons learned in Haiti to develop and test materials in other countries with high rates of canine rabies.

Perceptions and Practices of Mass Bat Exposure Events in the Setting of Rabies Among U.S. Public Health Agencies

Current guidelines in the setting of exposures to potentially rabid bats established by the Advisory Committee on Immunization Practices (ACIP) address post-exposure prophylaxis (PEP) administration in situations where a person may not be aware that a bite or direct contact has occurred and the bat is not available for diagnostic testing. These include instances when a bat is discovered in a room where a person awakens from sleep, is a child without an adult witness, has a mental disability or is intoxicated. The current ACIP guidelines, however, do not address PEP in the setting of multiple persons exposed to a bat or a bat colony, otherwise known as mass bat exposure (MBE) events. Due to a dearth of recommendations for response to these events, the reported reactions by public health agencies have varied widely. To address this perceived limitation, a survey of 45 state public health agencies was conducted to characterize prior experiences with MBE and practices to mitigate the public health risks. In general, most states (69% of the respondents) felt current ACIP guidelines were unclear in MBE scenarios. Thirty-three of the 45 states reported prior experience with MBE, receiving an average of 16.9 MBE calls per year and an investment of 106.7 person-hours annually on MBE investigations. PEP criteria, investigation methods and the experts recruited in MBE investigations varied between states. These dissimilarities could reflect differences in experience, scenario and resources. The lack of consistency in state responses to potential mass exposures to a highly fatal disease along with the large contingent of states dissatisfied with current ACIP guidance warrants the development of national guidelines in MBE settings.

Dog Ecology and Barriers to Canine Rabies Control in the Republic of Haiti, 2014-2015

An estimated 59 000 persons die annually of infection with the rabies virus worldwide, and dog bites are responsible for 95% of these deaths. Haiti has the highest rate of animal and human rabies in the Western Hemisphere. This study describes the status of animal welfare, animal vaccination, human bite treatment, and canine morbidity and mortality in Haiti in order to identify barriers to rabies prevention and control. An epidemiologic survey was used for data collection among dog owners during government-sponsored vaccination clinics at fourteen randomly selected sites from July 2014 to April 2015. A total of 2005 surveys were collected and data were analysed using parametric methods. Over 50% of owned dogs were allowed to roam freely, a factor associated with rabies transmission. More than 80% of dog owners reported experiencing barriers to accessing rabies vaccination for their dogs. Nearly one-third of the dog population evaluated in this study died in the year preceding the survey (32%) and 18% of these deaths were clinically consistent with rabies. Dog bites were commonly reported, with more than 3% of the study population bitten within the year preceding the survey. The incidence of canine rabies in Haiti is high and is exacerbated by low access to veterinary care, free-roaming dog populations and substandard animal welfare practices. Programmes to better understand the dog ecology and development of methods to improve access to vaccines are needed. Rabies deaths are at historical lows in the Western Hemisphere, but Haiti and the remaining canine rabies endemic countries still present a significant challenge to the goal of rabies elimination in the region.

Government Response to the Discovery of a Rabies Virus Reservoir Species on a Previously Designated Rabies-Free Island, Taiwan, 1999-2014

Taiwan had been considered rabies free since 1961. In 2013, Taiwan confirmed the detection of rabies virus in wild Taiwan ferret-badgers. Up to December 2014, there have been 423 rabies-confirmed ferret-badgers and three cases of spillover infection into non-reservoir hosts. Genetic analysis indicates that TFBV is distinct from all other known rabies virus variants. To date, ferret-badger rabies is known to occur only in China and Taiwan. The temporal dynamics of rabid ferret-badgers in Taiwan suggests that the epizootic appears to have subsided to enzootic levels as of December 2014. According to the current epidemiologic data, there is only one TFBV strain in Taiwan. TFBV is still sequestered to the mountainous regions. Humans are at risk mainly through exposure to the virus from infected domestic meso-carnivores, mainly dogs and cats. Dogs and cats should be vaccinated to establish an immunological barrier to stop the spread of the disease from mountainous regions to domestic meso-carnivores.

Clinical management and humoral immune responses to rabies post-exposure prophylaxis among three patients who received solid organs from a donor with rabies

BACKGROUND

The rabies virus causes a fatal encephalitis and can be transmitted through organ transplantation. In 2013, a man developed rabies 18 months after receiving a kidney from a donor with rabies, who was not known to have been infected when the organs were procured. Three additional persons who received organs from the same donor (liver, kidney, heart), all of whom were not vaccinated for rabies before transplantation, received rabies post-exposure prophylaxis (PEP) with rabies immune globulin and 5 doses of rabies vaccine as soon as the diagnosis of rabies was made in the donor (18 months after their transplant surgeries). We describe their clinical management.

METHODS

As the 3 recipients were all on immunosuppressive medications, post-vaccination serologic testing was performed using the rapid fluorescent focus inhibition test to measure rabies virus neutralizing antibodies (RVNAs). An acceptable antibody response to administration of rabies vaccine was defined as detection of RVNAs at a concentration ≥0.1 IU/mL from a serum specimen collected ≥7 days after the fifth vaccine dose.

RESULTS

All 3 recipients demonstrated an acceptable antibody response despite their immunosuppressed states. More than 36 months have passed since their transplant surgeries, and all 3 recipients have no evidence of rabies.

CONCLUSIONS

The survival of 3 previously unvaccinated recipients of solid organs from a donor with rabies is unexpected. Although the precise factors that led to their survival remain unclear, our data suggest that PEP can possibly enhance transplant safety in settings in which donors are retrospectively diagnosed with rabies.

A large-scale, rapid public health response to rabies in an organ recipient and the previously undiagnosed organ donor

This article describes and contrasts the public health response to two human rabies cases: one organ recipient diagnosed within days of symptom onset and the transplant donor who was diagnosed 18 months post-symptom onset. In response to an organ-transplant-related rabies case diagnosed in 2013, organ donor and recipient investigations were conducted by multiple public health agencies. Persons with potential exposure to infectious patient materials were assessed for rabies virus exposure. An exposure investigation was conducted to determine the source of the organ donor's infection. Over 100 persons from more than 20 agencies spent over 2700 h conducting contact investigations in healthcare, military and community settings. The 564 persons assessed include 417 healthcare workers [5.8% recommended for post-exposure prophylaxis (PEP)], 96 community contacts (15.6% recommended for PEP), 30 autopsy personnel (50% recommended for PEP), and 21 other persons (4.8% recommended for PEP). Donor contacts represented 188 assessed with 20.2% recommended for PEP, compared with 5.6% of 306 recipient contacts recommended for PEP. Human rabies cases result in substantial use of public health and medical resources, especially when diagnosis is delayed. Although rare, clinicians should consider rabies in cases of encephalitis of unexplained aetiology, particularly for cases that may result in organ donation.

Imported human rabies in Switzerland, 2012: a diagnostic conundrum

Human rabies is rare in Western Europe. It is not easily recognized in the absence of a history of exposure. We describe the clinical course, diagnosis and follow-up of an imported human rabies case in Switzerland. The patient, a U.S. citizen, presented at an outpatient clinic in Iraq with pain in his right shoulder on July 5, 2012. On July 8 he was transferred to a hospital in the United Arab Emirates, where he exhibited progressive encephalitis with coma. On July 29, he was transferred to a hospital in Switzerland, where he died on July 31, 2012. The autopsy showed severe encephalitis. Rabies was diagnosed by the rapid fluorescent focus inhibition test (RFFIT) and confirmed by fluorescence antibody testing (FAT) in brain smears and immunohistochemistry on paraffin-embedded brain sections. The viral strain was characterized by RT-PCR followed by sequencing and phylogenetic analysis as an American bat rabies strain associated with Tadarida brasiliensis. Close contacts and exposed health care workers received postexposure prophylaxis (PEP).

C-V measurements of micron diameter metal-oxide-semiconductor capacitors using a scanning-electron-microscope-based nanoprobe

The C-V electrical characterization of microstructures on a standard probe station is limited by the magnification of the imaging system and the precision of the probe manipulators. To overcome these limitations, we examine the combination of in situ electrical probing and a dual column scanning electron microscope/focused ion beam system. The imaging parameters and probing procedures are carefully chosen to reduce e-beam damage to the metal oxide semiconductor capacitor device under test. Estimation of shunt capacitance is critical when making femtofarad level measurements. C-V measurements of micron size metal-oxide-silicon capacitors are demonstrated.

Adsorption kinetics of p-nitrobenzenethiol self-assembled monolayers on a gold surface

The adsorption kinetics of octadecanethiol (ODT) and p-nitrobenzenethiol (NBT) from ethanol solutions has been studied by means of contact angle, optical ellipsometry, angle-resolved X-ray photoelectron spectroscopy (ARXPS), and grazing angle attenuated total reflection Fourier transform infrared (FTIR) measurements. ODT data were used as a reference for the kinetics studies of film growth. The growth of self-assembled monolayers from dilute solutions follows Langmuir isotherm adsorption kinetics. A saturated film is formed within 5 h after immersion in solutions of concentrations ranging from 0.0005 to 0.01 mM. The density of the monolayer depends on the concentration of the solution.

Secretory proteins compete for production in the mammary gland of transgenic mice

To explore the possibility that genes might compete for expression, we have studied transgenic mice producing high levels of the sheep milk protein, beta-lactoglobulin (BLG), in the mammary gland. Mice carrying one or more transgene loci expressed BLG in milk at levels ranging from 7 to 33 mg/ml. The effects of BLG synthesis on the levels of endogenous milk gene expression were examined. No significant increase in total milk protein concentration was recorded even in mice expressing the largest amounts of BLG. Measurement of individual milk proteins showed that transgene protein was manufactured at the expense of host protein synthesized in the gland. Whey acidic protein production was more suppressed than casein production. Suppression of endogenous proteins was matched by a reduction in the corresponding steady-state mRNA levels; in double-transgenic mice, which expressed the largest amounts of BLG, beta-casein and whey acidic protein mRNA populations were reduced to 75 and 56% of control levels respectively. We demonstrate that an exogenous gene competes effectively for expression with endogenous genes. Possible mechanisms of competition are discussed.

Restricted tissue-specific but correct developmental expression mediated by a short human alpha 1AT promoter fragment in transgenic mice

The tissue-specific and developmental pattern of expression controlled by the proximal promoter (position-348 to +15) derived from the human alpha-1-antitrypsin (h alpha 1AT) gene was studied in transgenic mice. The short promoter segment was linked to the chloramphenicol acetyltransferase (CAT) reporter gene. The transgene showed highly specific expression in the liver and the correct developmental pattern of regulation. Interestingly, this short promoter targets expression to the liver with a greater specificity than that reported for larger alpha 1AT promoter fragments.

Characterization of the ovine LH beta-subunit gene: the promoter directs gonadotrope-specific expression in transgenic mice

The alpha- and beta-subunits of the gonadotropin hormones are expressed in the gonadotrope cells of the anterior pituitary. There are no adequate in vitro systems for the analysis of beta-subunit gene expression. In this study, therefore, transgenic mice have been used to investigate the regulation of expression of the ovine luteinizing hormone beta-gene (oLH beta) in vivo. oLH beta was isolated, characterized, and 1.9 kb of the promoter fused to the bacterial reporter chloramphenicol acetyl-transferase (CAT). Three lines of transgenic mice were generated. CAT enzyme was detected in the pituitary of two lines, whereas the third line did not express. Measurement of endogenous luteinizing hormone and follicle stimulating hormone levels in both expressing lines revealed small differences when compared to controls, but these did not affect the fertility of the animals. Immunostaining of the anterior pituitary revealed that the oLH beta CAT transgene was expressed specifically in gonadotrope cells.

Fetal habituation to repeated sound stimulation

Habituation is the progressive decrement of response with repeated stimulation. Neonatologists use this phenomenon to assess newborns for various pathological conditions of the CNS. The present study examined the time required for habituation of the startle response in 103 fetuses at various gestational ages (32 to 40 weeks). The external stimulus was produced by a door buzzer (80 to 90 db). Habituation time decreased as gestational age increased. About 85% of the fetuses showed habituation after less than 20 stimuli, and about 95% after less than 30 stimuli. In all cases habituation time never exceeded 50 stimuli.

Temperature dependence of the binding of [3H]mepyramine and related compounds to the histamine H1 receptor

The extent of the promethazine-sensitive binding of [3H]mepyramine to a washed fraction from guinea pig cerebellum was little altered between 4 degrees and 30 degrees. The dissociation of [3H]mepyramine from the H1 receptor was markedly temperature-sensitive. An Arrhenius plot of the variation of the dissociation rate constant, k-1, with temperature was linear over the range 37 degrees -15 degrees (E alpha = 160 kJ mole-1). The association rate constant, k1, was also temperature-dependent, and an Arrhenius plot approximated well to a straight line between 30 degrees and 15 degrees (E alpha = 112 kJ mole-1). The linear relationship may hold down to 4 degrees. A consequence of the slow dissociation at 4 degrees is that the IC50 for mepyramine inhibition of promethazine-sensitive [3H]mepyramine binding at 4 degrees is independent of the concentration of [3H]mepyramine if the cerebellar homogenate is first incubated with the nonradioactive antagonist before addition of the 3H-ligand. Promethazine binding showed a temperature dependence similar to that of mepyramine, and for both antagonists and for chlorpromazine the affinity constant was not greatly increased (equal to or less than a factor of 2) at 4 degrees compared with 30 degrees. Tripelennamine showed a more rapid dissociation at 4 degrees than the other antagonists. Mequitazine dissociated slowly at 4 degrees, but the affinity constant was lower at 4 degrees than at 30 degrees.

Metastatic breast carcinoma in cerebrospinal fluid. A cytomorphometric study

A study was undertaken to quantitate the cellular characteristics of metastatic breast carcinoma in cerebrospinal fluid (CSF). Millipore filters of CSF from 15 patients with metastatic breast carcinoma were reviewed; 50 cells per case were evaluated when available. All cells in all cases shed singly or in loose clusters; tight balls or morulae were absent. All cells had regular, round-to-oval nuclei with finely granular chromatin. The majority of cells in all cases had single or multiple round nucleoli, granular cytoplasm with distinct borders and a mean nuclear-cytoplasmic ratio of close to 0.70. Cellular background, number of tumor cells per case, number and placement of nuclei and nuclear and cytoplasmic diameter varied both within and among the cases. There was significant variation in nuclear and cytoplasmic diameters both within and among the cases of infiltrating ductal carcinoma. Thus, the uniform appearance of the cells was due to consistent cytologic features, not to similarity in cell size. The cytologic profile of metastatic breast carcinoma is sufficiently characteristic to distinguish this tumor from other benign and malignant lesions that shed in the CSF.