Extremely anisotropic van der Waals thermal conductors.

The densification of integrated circuits requires thermal management strategies and high thermal conductivity materials1-3. Recent innovations include the development of materials with thermal conduction anisotropy, which can remove hotspots along the fast-axis direction and provide thermal insulation along the slow axis4,5. However, most artificially engineered thermal conductors have anisotropy ratios much smaller than those seen in naturally anisotropic materials. Here we report extremely anisotropic thermal conductors based on large-area van der Waals thin films with random interlayer rotations, which produce a room-temperature thermal anisotropy ratio close to 900 in MoS2, one of the highest ever reported. This is enabled by the interlayer rotations that impede the through-plane thermal transport, while the long-range intralayer crystallinity maintains high in-plane thermal conductivity. We measure ultralow thermal conductivities in the through-plane direction for MoS2 (57 ± 3 mW m-1 K-1) and WS2 (41 ± 3 mW m-1 K-1) films, and we quantitatively explain these values using molecular dynamics simulations that reveal one-dimensional glass-like thermal transport. Conversely, the in-plane thermal conductivity in these MoS2 films is close to the single-crystal value. Covering nanofabricated gold electrodes with our anisotropic films prevents overheating of the electrodes and blocks heat from reaching the device surface. Our work establishes interlayer rotation in crystalline layered materials as a new degree of freedom for engineering-directed heat transport in solid-state systems.

Joint scores in hemophilic arthropathy in children: Developing country perspectives.

OBJECTIVE: Hemophilia is a common X-linked recessive coagulopathy causing recurrent bleeding into the synovial joints and results in articular and periarticular abnormalities. To our knowledge, this is the first comprehensive study aimed at studying the clinico-radiological joint score evaluation in hemophilic arthropathy in children from a developing country and its possible impact on the quality of life. METHODS: In this hospital-based, prospective, descriptive study, all children presenting to the pediatric rheumatology clinic were studied. The joint physical examination was scored using the Hemophilia Joint Health Score 2.1 (HJHS 2.1). The patients were then subjected to imaging of the most affected joint using ultrasonography (USG) and magnetic resonance imaging (MRI). Detailed USG and MRI radiological evaluation was recorded in the predesigned proforma using the Hemophilia Early Arthropathy Detection with Ultra Sound (HEAD-US) score and MRI DENVER score. The physical quality of life as per Functional Independence Score in Hemophilia (FISH) was noted. The clinical, radiological, and functional scores were analyzed with an appropriate statistical measure. RESULTS: The mean age at presentation was 7.4 years (interquartile range 4.9-10), with the knee being the most common joint involved. All of the USG score, MRI score, and FISH score have a significant correlation (p<0.05), with the HJHS 2.1 score with correlation coefficients of 0.7086, -0.8916, and 0.8607, respectively. USG and MRI had a correlation coefficient of -0.7145 and -0.8326 with FISH, respectively. CONCLUSION: The degree of association between HJHS 2.1 score was found to be maximum with HEAD-US score, whereas a negative correlation was seen evaluating FISH score with both HEAD-US and MRI DENVER scores. Use of these scores, specifically HEAD-US score, will result in consistent assessment of hemophilic joints, optimizing the management of the destructive changes.

Ultrahigh thermal conductivity in isotope-enriched cubic boron nitride.

Materials with high thermal conductivity (κ) are of technological importance and fundamental interest. We grew cubic boron nitride (cBN) crystals with controlled abundance of boron isotopes and measured κ greater than 1600 watts per meter-kelvin at room temperature in samples with enriched 10B or 11B. In comparison, we found that the isotope enhancement of κ is considerably lower for boron phosphide and boron arsenide as the identical isotopic mass disorder becomes increasingly invisible to phonons. The ultrahigh κ in conjunction with its wide bandgap (6.2 electron volts) makes cBN a promising material for microelectronics thermal management, high-power electronics, and optoelectronics applications.

Neonatal septic arthritis: Indian perspective.

OBJECTIVE: To delineate the pattern of joint involvement in neonatal septic arthritis, assess the prognosis, and determine significant predictors of unfavorable outcome. METHODS: Subjects were recruited through purposive sampling after obtaining parental consent. A detailed history and examination findings with perinatal data were recorded. Ultrasound and magnetic resonance imaging data of affected joints and blood culture and aspirated joint fluid culture data were recorded along with management received. Cases were followed-up every 3 months from discharge up to minimum 12 months. An unfavorable outcome indicated by permanent joint deformity or restricted range of movement of the affected joint, limb length discrepancy, and persistent joint deformity upon radio imaging at the end of the follow-up period were also included. RESULTS: The hip joint involvement (59.2%) was the commonest with predominance of the monoarticular pattern of affliction (74.4%). An overall outcome was favorable in 70.3% subjects with prompt diagnosis and management. A delay in seeking treatment was found to be an indicator of unfavorable outcome. In addition, disease detection by ultrasound at presentation predicted unfavorable outcome. CONCLUSION: Neonatal septic arthritis is a rare disease with predominant hip or knee involvement. Outcome is favorable with early detection and institution of appropriate management. A delay in treatment worsens prognosis.

Abandoned Babies at Tertiary Care Rural Medical College Hospital: The Indian Scenarios.

OBJECTIVES: In India, girls are sex-selectively abandoned. The abandoned babies are brought to the nearest hospital under the jurisdiction of the administration. The authors aimed to study the demographic data and disease profile of those babies. METHODS: In this hospital-based, retrospective, descriptive study, authors studied all the abandoned babies who were admitted to the Department of Pediatrics as "unknown" and cared for over the last 3 y. Their case records were analyzed with an appropriate statistical measure. RESULTS: Out of 11 babies, girl-boy ratio was 2.6:1, 73% being abandoned in the neonatal period with a survival rate of 91%. Six babies (54.5%) required emergency intervention at admission. Hospital stay was higher in girls with mean discharge time being 106 d, although the mean fit for discharge time was 6.5 d. CONCLUSIONS: This study is the first of its kind on abandoned babies demographic data and disease profile, highlighting the burden of abandoned babies in the hospital.

Accumulation of Nucleolar Inorganic Polyphosphate Is a Cellular Response to Cisplatin-Induced Apoptosis.

The chemotherapeutic drug cisplatin, which targets DNA, serves as one of the main staples in cancer treatment. Yet, the therapeutic application of cisplatin is limited by two major challenges: the occurrence of reversible and irreversible side effects due to non-specific toxicity, and the intrinsic or developing resistance of tumor cells toward cisplatin. Here we demonstrate that cancer cells respond to cisplatin treatment with the nucleolar accumulation of inorganic polyphosphate (polyP), a universally conserved high-energy compound. PolyP accumulation positively correlates with the levels of activated caspase-3, suggesting a novel role of polyP in cisplatin-mediated apoptosis. In support of this finding, we discovered that administration of exogenous polyP increases cisplatin-induced toxicity in select cancer cell lines, raising the exciting possibility that enhancing endogenous polyP levels might be a novel mechanism to sensitize cancer cells to cisplatin treatment.