Natural History of Cryptosporidiosis in a Birth Cohort in Southern India.

BACKGROUND: Cryptosporidium is a leading cause of moderate to severe childhood diarrhea in resource-poor settings. Understanding the natural history of cryptosporidiosis and the correlates of protection are essential to develop effective and sustainable approaches to disease control and prevention. METHODS: Children (N = 497) were recruited at birth in semiurban slums in Vellore, India, and followed for 3 years with twice-weekly home visits. Stool samples were collected every 2 weeks and during diarrheal episodes were tested for Cryptosporidium species by polymerase chain reaction (PCR). Serum samples obtained every 6 months were evaluated for seroconversion, defined as a 4-fold increase in immunoglobulin G directed against Cryptosporidium gp15 and/or Cp23 antigens between consecutive sera. RESULTS: Of 410 children completing follow-up, 397 (97%) acquired cryptosporidiosis by 3 years of age. PCR identified 1053 episodes of cryptosporidiosis, with an overall incidence of 0.86 infections per child-year by stool and serology. The median age for the first infection was 9 (interquartile range, 4-17) months, indicating early exposure. Although infections were mainly asymptomatic (693 [66%]), Cryptosporidium was identified in 9.4% of diarrheal episodes. The proportion of reinfected children was high (81%) and there was clustering of asymptomatic and symptomatic infections (P < .0001 for both). Protection against infection increased with the order of infection but was only 69% after 4 infections. Cryptosporidium hominis (73.3%) was the predominant Cryptosporidium species, and there was no species-specific protection. CONCLUSIONS: There is a high burden of endemic cryptosporidiosis in southern India. Clustering of infection is suggestive of host susceptibility. Multiple reinfections conferred some protection against subsequent infection.

Impact of regulatory spin of pioglitazone on prescription of antidiabetic drugs among physicians in India: A multicentre questionnaire-based observational study.

Background & objectives: Pioglitazone was suspended for manufacture and sale by the Indian drug regulator in June 2013 due to its association with urinary bladder carcinoma, which was revoked within a short period (July 2013). The present questionnaire-based nationwide study was conducted to assess its impact on prescribing behaviour of physicians in India. Methods: Between December 2013 and March 2014, a validated questionnaire was administered to physicians practicing diabetes across 25 centres in India. Seven hundred and forty questionnaires fulfilling the minimum quality criteria were included in the final analysis. Results: Four hundred and sixteen (56.2%) physicians prescribed pioglitazone. Of these, 281 used it in less than the recommended dose of 15 mg/day. Most physicians (94.3%) were aware of recent regulatory events. However, only 333 (44.8%) changed their prescribing pattern. Seventeen of the 416 (4.1%) physicians who prescribed pioglitazone admitted having come across at least one type 2 diabetes mellitus patient (T2DM) who had urinary bladder carcinoma, and of these 13 said that it was in patients who took pioglitazone for a duration of more than two years. Only 7.8 per cent of physicians (n=58) categorically advocated banning pioglitazone, and the rest opined for its continuation or generating more evidence before decision could be taken regarding its use in T2DM. Interpretation & conclusions: Majority of the physicians though were aware of the regulatory changes with regard to pioglitazone, but their prescribing patterns were not changed for this drug. However, it was being used at lower than the recommended dose. There is a need for generating more evidence through improved pharmacovigilance activities and large-scale population-based prospective studies regarding the safety issues of pioglitazone, so as to make effectual risk-benefit analysis for its continual use in T2DM.

Low-dimensional boron structures based on icosahedron B12.

One-dimensional icosahedral boron chains and two-dimensional icosahedral boron sheets (icosahedral α, δ6, and δ4 sheets) that contain icosahedra B12 as their building units have been predicted in a computer simulation study using a state-of-the-art semi-empirical Hamiltonian. These novel low-dimensional icosahedral structures exhibit interesting bonding and electronic properties. Specifically, the three-center, two-electron bonding between icosahedra B12 of the boron bulk (rhombohedral boron) transforms into a two-center bonding in these new allotropes of boron sheets. In contrast to the previously reported stable buckled α and triangular boron monolayer sheets, these new allotropes of boron sheets form a planar network. Calculations of electronic density of states (DOS) reveal a semiconducting nature for both the icosahedral chain and the icosahedral δ6 and δ4 sheets, as well as a nearly gapless (or metallic-like) feature in the DOS for the icosahedral α sheet. The results for the energy barrier per atom between the icosahedral δ6 and α sheets (0.17 eV), the icosahedral δ6 and δ4 sheets (0.38 eV), and the icosahedral α and δ4 sheets (0.27 eV), as indicated in the respective parentheses, suggest that these new allotropes of boron sheets are relatively stable.

Next generation of the self-consistent and environment-dependent Hamiltonian: Applications to various boron allotropes from zero- to three-dimensional structures.

An upgrade of the previous self-consistent and environment-dependent linear combination of atomic orbitals Hamiltonian (referred as SCED-LCAO) has been developed. This improved version of the semi-empirical SCED-LCAO Hamiltonian, in addition to the inclusion of self-consistent determination of charge redistribution, multi-center interactions, and modeling of electron-electron correlation, has taken into account the effect excited on the orbitals due to the atomic aggregation. This important upgrade has been subjected to a stringent test, the construction of the SCED-LCAO Hamiltonian for boron. It was shown that the Hamiltonian for boron has successfully characterized the electron deficiency of boron and captured the complex chemical bonding in various boron allotropes, including the planar and quasi-planar, the convex, the ring, the icosahedral, and the fullerene-like clusters, the two-dimensional monolayer sheets, and the bulk alpha boron, demonstrating its transferability, robustness, reliability, and predictive power. The molecular dynamics simulation scheme based on the Hamiltonian has been applied to explore the existence and the energetics of ∼230 compact boron clusters BN with N in the range from ∼100 to 768, including the random, the rhombohedral, and the spherical icosahedral structures. It was found that, energetically, clusters containing whole icosahedral B12 units are more stable for boron clusters of larger size (N > 200). The ease with which the simulations both at 0 K and finite temperatures were completed is a demonstration of the efficiency of the SCED-LCAO Hamiltonian.

Theoretical predictions of a bucky-diamond SiC cluster.

A study of structural relaxations of Si(n)C(m) clusters corresponding to different compositions, different relative arrangements of Si/C atoms, and different types of initial structure, reveals that the Si(n)C(m) bucky-diamond structure can be obtained for an initial network structure constructed from a truncated bulk 3C-SiC for a magic composition corresponding to n = 68 and m = 79. This study was performed using a semi-empirical Hamiltonian (SCED-LCAO) since it allowed an extensive search of different types of initial structures. However, the bucky-diamond structure predicted by this method was also confirmed by a more accurate density functional theory (DFT) based method. The bucky-diamond structure exhibited by a SiC-based system represents an interesting paradigm where a Si atom can form three-coordinated as well as four-coordinated networks with carbon atoms and vice versa and with both types of network co-existing in the same structure. Specifically, the bucky-diamond structure of the Si(68)C(79) cluster consists of a 35-atom diamond-like inner core (four-atom coordinations) suspended inside a 112-atom fullerene-like shell (three-atom coordinations).

Completeness of reporting and outcome switching in trials published in Indian journals from 2017 to 2019: A cross-sectional study.

Context: Randomized controlled trials (RCTs) are among the cornerstones for generation of high-quality clinical evidence. However, incomplete or biased reporting of trials can hamper the process of review of trials and their results. Outcome switching, intentional, or otherwise leads to biased reporting and can result in false inferences. Aims: The aim of this study was to analyze the completeness of reporting Consolidated Standards of Reporting Trials (CONSORT) 2010 checklist items and detect if outcome switching had occurred. Settings and Design: This cross-sectional study was conducted in the department of pharmacology. Methods: Online editions of journals published by the Indian association of medical specialties from 2017 to 2019 were accessed, and the full-text versions of the published RCTs in them were downloaded. Reporting of each item in the CONSORT checklist was recorded. The effect of trial registration and CONSORT endorsement on reporting of key methodological parameters was also determined. Protocols of registered trials were accessed, and the outcome switching was assessed. Statistical Analysis Used: Descriptive statistics were used to summarize the data. Results: Average completeness of reporting has significantly improved from 2017 to 2019. Major areas of underreporting were generalizability, protocol availability, trial registration, date of recruitment, allocation concealment, and the patient flow diagram. CONSORT endorsing journals had worse, whereas registered trials had better reporting of key methodological indicators. No overt switching of outcomes was observed in 84 out of 86 registered trials where trial protocols were available online for comparison. Conclusions: Quality of clinical trial reporting in the Indian medical journals has improved but remains inadequate. CONSORT nonendorsement prevents completeness of trial reporting.

Comparative analysis of safety and efficacy of Alcaftadine 0.25%, Olopatadine hydrochloride 0.2% and Bepotastine besilate 1.5% in allergic conjunctivitis.

Purpose: To compare the efficacy and safety of Alcaftadine 0.25%, Olopatadine hydrochloride 0.2%, and Bepotastine besilate 1.5% ophthalmic solutions in the treatment of allergic conjunctivitis. Methods: This is a prospective, observer-masked, comparative study of 180 patients with mild to moderate allergic conjunctivitis, randomized into three groups of 60 patients each. Each group was assigned to be treated with one of the three treatment options namely Alcaftadine 0.25%, Olopatadine hydrochloride 0.2% and Bepotastine besilate 1.5% ophthalmic solutions. Patients were followed-up at regular intervals with relief and resolution of symptoms and signs noted using Total Ocular Scoring System (TOSS) and hyperaemia scale. Results: All three topical medications were effective in resolving symptoms of the patients with mild to moderate allergic conjunctivitis. Baseline mean TOSS scores for Alcaftadine group, Olopatadine group and Bepotastine besilate group were (7.68±2.32), (7.65±2.32) and (7.45±2.27) respectively as compared to the corresponding TOSS scores on 14th Day (4th visit) which were (0.2 ± 0.43), (0.4 ± 0.56) and (0.1 ± 0.36) respectively. The resolution of symptoms in the Bepotastine and Alcaftadine groups was significantly profound as compared to the Olopatadine group (p = 0.008). Bepotastine and Alcaftadine groups significantly reduced allergic conjunctivitis symptoms compared to Olopatadine group (p = 0.008). Conclusion: All three topical ophthalmic medications used in the study are safe and effective in the treatment of allergic conjunctivitis. However, Bepotastine and Alcaftadine appear to outweigh Olopatadine in resolving the symptoms of allergic conjunctivitis.

Electrostatic deposition of graphene in a gaseous environment: a deterministic route for synthesizing rolled graphenes?

The synthesis of single-wall carbon nanotubes of desired diameters and chiralities is critical to the design of nanoscale electronic devices with desired properties. The existing methods are based on self-assembly, therefore lacking control over the diameters and chiralities. The present work reports a direct route for rolling graphene. Specifically, we found that the electrostatic deposition of graphene yielded: (i) flat graphene layers under high vacuum (10(-7) Torr), (ii) completely scrolled graphene under hydrogen atmosphere, (iii) partially scrolled graphene under nitrogen atmosphere, and (iv) no scrolling for helium atmospheres. Our study shows that the application of the electrostatic field facilitates the rolling of graphene sheets exposed to appropriate gases and allows the rolling of any size of graphene. The technique proposed here, in conjunction with a technique that produces graphene nanoribbons of uniform widths, will have significant impact on the development of carbon nanotube based devices. Furthermore, the present technique may be applied to obtain tubes/scrolls of other layered materials.

Energetics, relative stabilities, and size-dependent properties of nanosized carbon clusters of different families: fullerenes, bucky-diamond, icosahedral, and bulk-truncated structures.

Structures and relative stabilities of carbon clusters belonging to different families have been investigated for diameters d < or = 5 nm based on an efficient semiempirical molecular dynamics (MD) scheme as well as a density functional theory based simulation. Carbon clusters studied include fullerenes and fullerene-derived structures (e.g., cages and onions), icosahedral structures, bucky-diamond structures, and clusters cut from the bulk diamond with spherical and facetted truncations. The reason for using a semiempirical MD is partly due to the large number of different cases (or carbon allotropes) investigated and partly due to the size of the clusters investigated in this work. The particular flavor of the semiempirical MD scheme is based on a self-consistent and environment-dependent Hamiltonian developed in the framework of linear combination of atomic orbitals. We find that (i) among the families of carbon clusters investigated, fullerene structures have the lowest energy with the relative energy ordering being E(fullerene) < E(onion) < E(icosahedral) < E(bucky-diamond) < E(bulk-truncated), (ii) a crossover between bucky-diamond and icosahedral structures is likely at d approximately 8 nm, (iii) the highest occupied molecular orbital-lowest unoccupied molecular orbital gap as a function of the diameter for the case of fullerenes shows an oscillatory behavior with the gap ranging from 2 eV to 6 meV, and the gap approaching that of gapless graphite for d > 3.5 nm, and (iv) there can be three types of phase transformations depending on the manner of heating and cooling in our simulated annealing studies: (a) a bucky-diamond structure --> an onionlike structure, (b) an onionlike --> a cage structure, and (c) a bucky-diamond --> a cage structure.

Cerebral venous thrombosis in Saudi Arabia. Clinical variables, response to treatment, and outcome.

OBJECTIVE: To investigate cerebral venous thrombosis (CVT) clinical presentations, risk factors, and response to treatment in Saudi Arabia. METHODS: Retrospective analysis of the King Fahad Medical City, Riyadh, acute stroke database from April 2005 through February 2008 revealed 22 patients with CVT. Hypercoagulable work-up and neuroimaging were performed. RESULTS: Sixteen patients were female (72.7%), and the median age was 35 years. Clinical presentations included: headache (77.3%), seizures (54.5%), focal neurological signs (54.5%), and decreased level of consciousness (50%). Over two-thirds (n=11; 69%) of female patients had a history of oral contraceptive use, which was the most common risk factor. Protein S deficiency (n=3), antiphospholipid antibody syndrome secondary to systemic lupus erythematosus (SLE) (n=1), rhinocerebral mucormycosis (n=1), leukemia (n=1), non-Hodgkin`s lymphoma (n=1), sepsis (n=1), and unknown (n=6) were causes. Affected areas included superior sagittal (n=13), transverse (n=16), sigmoid (n=14), straight (n=6), and cavernous sinus (n=1); internal cerebral vein (n=2); vein of Galen (n=3); cortical veins (n=10); and internal jugular vein (n=12). Two patients had quadriparesis, and 2 patients died. The remainder (n=18, 81.8%) improved. Bilateral hemorrhagic presentation or venous infarction, deep venous system thrombosis, and underlying malignancy had less favorable results. CONCLUSION: Presentations in our series were similar to those in other reports, although altered consciousness and seizures were more common. Cortical vein involvement was also higher than commonly reported. Oral contraceptive use was a primary risk factor in female patients. Outcomes were favorable in 81.8% of patients.

Drug dispensing practices at pharmacies in Bengaluru: A cross-sectional study.

OBJECTIVES: Pharmacists are one of the crucial focal points for health care in the community. They have tremendous outreach to the public as pharmacies are often the first-port-of-call. With the increase of ready-to-use drugs, the main health-related activity of a pharmacist today is to assure the quality of dispensing, a key element to promote rational medicine use. MATERIALS AND METHODS: A cross-sectional study of 200 pharmacies, 100 each in various residential (R) and commercial (C) areas of Bengaluru, was conducted using a prevalidated questionnaire administered to the chief pharmacist or the person-in-charge by the investigators. RESULTS: Dispensing without prescription at pharmacies was 45% of the total dispensing encounters and significantly higher (χ2 = 15.2, P < 0.001, df = 1) in pharmacies of residential areas (46.64%) as compared to commercial areas (43.64%). Analgesics were the most commonly dispensed drugs (90%) without prescription. Only 31% insisted on dispensing full course of antibiotics prescribed and 19% checked for completeness of prescription before dispensing. Although 97% of the pharmacies had a refrigerator, 31% of these did not have power back-up. Only about 50% of the pharmacists were aware of Schedule H. CONCLUSION: This study shows a high proportion of dispensing encounters without prescription, a higher rate of older prescription refills, many irregularities in medication counseling and unsatisfactory storage practices. It also revealed that about half of the pharmacists were unaware of Schedule H and majority of them about current regulations. Hence, regulatory enforcement and educational campaigns are a prerequisite to improve dispenser's knowledge and dispensing practices.

Initial stage of growth of single-walled carbon nanotubes: modeling and simulations.

Because there are different pathways to grow carbon nanotubes (CNTs), a common mechanism for the synthesis of CNTs does not likely exist. However, after carbon atoms are liberated from carbon-containing precursors by catalysts or from pure carbon systems, a common feature, the nucleation of CNTs by electron mediation, does appear. We studied this feature using the initial stage of growth of single wall CNTs (SWCNTs) by transition metal nano-particle catalysts as the working example. To circumvent the bottleneck due to the size and simulation time, we used a model in which the metal droplet is represented by a jellium, and the effect of collisions between the carbon atoms and atoms of the catalyst is captured by charge transfers between the jellium and the carbon. The simulations were performed using a transferable semi-empirical Hamiltonian to model the interactions between carbon atoms in jellium. We annealed different initial configurations of carbon clusters in jellium as well as in a vacuum. We found that in jellium, elongated open tubular structures, precursors to the growth of SWCNTs, are formed. Our model was also shown to be capable of mimicking the continued growth when more atoms were placed near the open end of the tubular structure.

Colossal paramagnetic moments in metallic carbon nanotori.

Carbon nanostructures with unusually large paramagnetic moments have been discovered in a theoretical study of the electronic and magnetic properties of carbon nanotubes bent into toroids. Specifically, nanotori formed from metallic nanotubes with lambda(F) = 3T, where lambda(F) is the Fermi wavelength and T the translation vector of the nanotube, exhibit giant paramagnetic moments at selected radii ("magic radii"), while the ones with lambda(F) = T are paramagnetic at any radius. The large paramagnetic moment is due to the interplay between the toroidal geometry and the ballistic motion of the pi electrons in the metallic nanotube.

Phonon spectromicroscopy of carbon nanostructures with atomic resolution.

The vibrational properties of single-wall carbon nanotubes have been probed locally with atomic-scale resolution by inelastic electron tunneling spectroscopy with a low-temperature scanning tunneling microscope. The high spatial resolution has allowed the unraveling of changes in the local phonon spectrum related to topological defects. We demonstrated that the radial breathing mode is suppressed within tube segments of lengths below approximately 3 nm, and that in the cap region phonon modes characteristic of the fullerene hemisphere are emerging. Phonon spectromicroscopy should lead to a better understanding of the mechanisms that limit the transport of heat or electrical charge inside nanostructured carbon materials.

Quantum interference and ballistic transmission in nanotube electron waveguides.

The electron transport properties of well-contacted individual single-walled carbon nanotubes are investigated in the ballistic regime. Phase coherent transport and electron interference manifest as conductance fluctuations as a function of Fermi energy. Resonance with standing waves in finite-length tubes and localized states due to imperfections are observed for various Fermi energies. Two units of quantum conductance 2G(0) = 4e(2)/h are measured for the first time, corresponding to the maximum conductance limit for ballistic transport in two channels of a nanotube.

Cerebral venous thrombosis in Saudi Arabia. Clinical variables, response to treatment, and outcome

To investigate cerebral venous thrombosis [CVT] clinical presentations, risk factors, and response to treatment in Saudi Arabia. Retrospective analysis of the King Fahad Medical City, Riyadh, acute stroke database from April 2005 through February 2008 revealed 22 patients with CVT. Hypercoagulable work-up and neuroimaging were performed. Sixteen patients were female [72.7%], and the median age was 35 years. Clinical presentations included: headache [77.3%], seizures [54.5%], focal neurological signs [54.5%], and decreased level of consciousness [50%]. Over two-thirds [n=11; 69%] of female patients had a history of oral contraceptive use, which was the most common risk factor. Protein S deficiency [n=3], antiphospholipid antibody syndrome secondary to systemic lupus erythematosus [SLE] [n=1], rhinocerebral mucormycosis [n=1], leukemia [n=1], non-Hodgkin's lymphoma [n=1], sepsis [n=1], and unknown [n=6] were causes. Affected areas included superior sagittal [n=13], transverse [n=16], sigmoid [n=14], straight [n=6] and cavernous sinus [n=1]; internal cerebral vein [n=2]; vein of Galen [n=3]; cortical veins [n=10]; and internal jugular vein [n=12]. Two patients had quadriparesis, and 2 patients died. The remainder [n=18, 81.8%] improved. Bilateral hemorrhagic presentation or venous infarction, deep venous system thrombosis, and underlying malignancy had less favorable results. Presentations in our series were similar to those in other reports, although altered consciousness and seizures were more common, Cortical vein involvement was also higher than commonly reported. Oral contraceptive use was a primary risk factor in female patients. Outcomes were favorable in 81.8% of patients