Low-Voltage DC-DC Converter for IoT and On-Chip Energy Harvester Applications.

The power saving issue and clean energy harvesting for wireless and cost-affordable electronics (e.g., IoT applications, sensor nodes or medical implants), have recently become attractive research topics. With this in mind, the paper addresses one of the most important parts of the energy conversion system chain - the power management unit. The core of such a unit will be formed by an inductorless, low-voltage DC-DC converter based on the cross-coupled dynamic-threshold charge pump topology. The charge pump utilizes a power-efficient ON/OFF regulation feedback loop, specially designed for strict low-voltage start-up conditions by a driver booster. Taken together, they serve as the masters to control the charge pump output (up to 600 mV), depending on the voltage value produced by a renewable energy source available in the environment. The low-power feature is also ensured by a careful design of the hysteresis-based bulk-driven comparator and fully integrated switched-capacitor voltage divider, omitting the static power consumption. The presented converter can also employ the on-chip RF-based energy harvester for use in a wireless power transfer system.

Association between histological alterations in the thymus and sudden infant death syndrome.

INTRODUCTION: Sudden infant death syndrome (SIDS) involves the death of an infant during the first year of life and it is among the leading causes of infant mortality worldwide. One hypothesis regarding the pathogenesis of SIDS is that it results from a combination of three independent factors: endogenous vulnerability, a critical time window during postnatal development, and exogenous stressors. This hypothesis is known as the "triple-risk model". METHODS: In this study, we used an immunohistological approach to compare the cellular microenvironments of thymuses from 19 infants whose sudden death was classified as SIDS and a control group, which consisted of thymuses from age-matched children undergoing surgery for various congenital heart defects. We hypothesized that morphological signs of stress-related thymic involution would be present. RESULTS: Based on our observations, we found evidence that the proliferation and maturation of T-lymphocytes in the thymuses of infants with SIDS were suppressed. We observed enhanced macrophage activity, suggesting an increase in the apoptosis of lymphocytes and decrease in number of thymic dendritic cells and myoid cells. Significant apoptosis of thymic lymphocytes without cell regeneration typically leads to atrophy of the thymus. All cellular events we observed resemble the initial stage of stress-related thymic involution. CONCLUSION: These results support the "triple-risk model," suggesting that certain exogenous stressors might be involved in the pathogenesis of SIDS. This was probably not recognized during the autopsies of infants who died suddenly.

Cytokines, growth, and environment factors in bone marrow plasma of acute lymphoblastic leukemia pediatric patients.

Acute lymphoblastic leukemia (ALL) cells depend on the microenvironment of the host in vivo and do not survive in in vitro culture. Conversely, the suppression of non-malignant tissues is one of the leading characteristics of the course of ALL. Both the non-malignant suppression and malignant cell survival may be partly affected by soluble factors within the bone marrow (BM) environment. Here, we aimed to identify proteins in BM plasma of children with ALL that may contribute to ALL aggressiveness and/or the microenvironment-mediated survival of ALL cells. LBMp (leukemic bone marrow plasma) at the time of ALL diagnosis was compared to control plasma of bone marrow (CBMp) or peripheral blood (CPBp) using a cytokine antibody array. The cytokine antibody array enabled simultaneous detection of 79 proteins per sample. Candidate proteins exhibiting significantly different profiles were further analyzed and confirmed by ELISA. mRNA expression of one of the candidate proteins (TIMP1) was studied using quantitative reverse transcriptase polymerase chain reaction (qRTPCR). The cytokine antibody array experiments identified 23 proteins that differed significantly (p<0.05); of these, two proteins (TIMP1 and LIF) withstood the Bonferroni correction. In contrast, little difference was observed between CBMp and CPBp. At the diagnosis of ALL, changes in the soluble microenvironment are detectable in BM plasma. These changes probably participate in the pathogenesis and/or result from the changes in the cell composition.

[Separation of sperm by micromanipulator from unusual forensic sample - case report]. / Separace spermií pomocí mikromanipulátoru z neobvyklého forenzního vzorku - kazuistika.

The aim of this study is to provide an information about the method of processing of unusual forensic sample that was submitted for the sexual assault case. We analyzed microscopic sample of vaginal swab stained using the hematoxylin-eosin mixture. After removing the covering glass we failed to collect the sperm cells to the micromanipulator capillary. The cells even started, due to the mechanical stress, to fall apart. We think that the main reason of the microdissection failure is the advanced cell lysis. Due to the negative results of the DNA analysis we defined a set of preventive and corrective actions that would (in case of application) increase the chance of positive identification in similar sexual assault cases.

High expression of cytoskeletal protein drebrin in TEL/AML1pos B-cell precursor acute lymphoblastic leukemia identified by a novel monoclonal antibody.

The expression of drebrin, a cytoskeletal protein newly estimated by expression profiling to correlate with the genotype and prognosis of B-cell precursor acute lymphoblastic leukemia (BCP-ALL), was examined by independent methods. After demonstrating its higher expression in TEL/AML1(pos) BCP-ALL by quantitative reverse transcriptase polymerase chain reaction, we developed an anti-drebrin monoclonal antibody (mAb). In a cohort of 86 children with BCP-ALL, we found increased expression of drebrin in TEL/AML1(pos) ALL. In conclusion, relationship of drebrin expression and prognosis or genotype can now be assessed using flow cytometry.