The Putative Endoglucanase PcGH61D from Phanerochaete chrysosporium Is a Metal-Dependent Oxidative Enzyme that Cleaves Cellulose

Many fungi growing on plant biomass produce proteins currently classified as glycoside hydrolase family 61 (GH61), some of which are known to act synergistically with cellulases. In this study we show that PcGH61D, the gene product of an open reading frame in the genome of Phanerochaete chrysosporium, is an enzyme that cleaves cellulose using a metal-dependent oxidative mechanism that leads to generation of aldonic acids. The activity of this enzyme and its beneficial effect on the efficiency of classical cellulases are stimulated by the presence of electron donors. Experiments with reduced cellulose confirmed the oxidative nature of the reaction catalyzed by PcGH61D and indicated that the enzyme may be capable of penetrating into the substrate. Considering the abundance of GH61-encoding genes in fungi and genes encoding their functional bacterial homologues currently classified as carbohydrate binding modules family 33 (CBM33), this enzyme activity is likely to turn out as a major determinant of microbial biomass-degrading efficiency

Shake-off of loosely bound electrons in Auger decays of Kr 2p core hole states

Multicharged Kr ions have been measured using monochromatized undulator radiation combined with a coincidence technique. It has been found that a charge-state distribution of Kr ions being coincident with satellite peaks of Kr 2p3/2 photoelectron is slightly different from that for the main line. Resonant Auger peaks for 2p–1nl-->1G4 nl transitions generated essentially Kr4+ only, which differs from the charge-state distribution for the normal Auger peak. These findings suggest that loosely bound electrons in high Rydberg orbitals are easily shaken-off in electron emission processes.Erratum is added on the last page

A practical device for pinpoint delivery of molecules into multiple neurons in culture

We have developed a device for pinpoint delivery of chemicals, proteins, and nucleic acids into cultured cells. The principle underlying the technique is the flow of molecules from the culture medium into cells through a rupture in the plasma membrane made by a needle puncture. DNA transfection is achieved by stabbing the needle tip into the nucleus. The CellBee device can be attached to any inverted microscope, and molecular delivery can be coupled with conventional live cell imaging. Because the position of the needle relative to the targeted cultured cells is computer-controlled, efficient delivery of molecules such as rhodamine into as many as 100 HeLa cells can be completed in 10 min. Moreover, specific target cells within a single dish can be transfected with multiple DNA constructs by simple changes of culture medium containing different plasmids. In addition, the nano-sized needle tip enables gentle molecular delivery, minimizing cell damage. This method permits DNA transfection into specific hippocampal neurons without disturbing neuronal circuitry established in culture

Radiation and the Risk of Chronic Lymphocytic and Other Leukemias among Chornobyl Cleanup Workers

Background: Risks of most types of leukemia from exposure to acute high doses of ionizing radiation are well known, but risks associated with protracted exposures, as well as associations between radiation and chronic lymphocytic leukemia (CLL), are not clear.
 Objectives: We estimated relative risks of CLL and non-CLL from protracted exposures to low-dose ionizing radiation.
 Methods: A nested case–control study was conducted in a cohort of 110,645 Ukrainian cleanup workers of the 1986 Chornobyl nuclear power plant accident. Cases of incident leukemia diagnosed in 1986–2006 were confirmed by a panel of expert hematologists/hematopathologists. Controls were matched to cases on place of residence and year of birth. We estimated individual bone marrow radiation doses by the Realistic Analytical Dose Reconstruction with Uncertainty Estimation (RADRUE) method. We then used a conditional logistic regression model to estimate excess relative risk of leukemia per gray (ERR/Gy) of radiation dose.
 Results: We found a significant linear dose response for all leukemia [137 cases, ERR/Gy = 1.26 (95% CI: 0.03, 3.58]. There were nonsignificant positive dose responses for both CLL and non-CLL (ERR/Gy = 0.76 and 1.87, respectively). In our primary analysis excluding 20 cases with direct in-person interviews less than 2 years from start of chemotherapy with an anomalous finding of ERR/Gy = –0.47 (95% CI: less than –0.47, 1.02), the ERR/Gy for the remaining 117 cases was 2.38 (95% CI: 0.49, 5.87). For CLL, the ERR/Gy was 2.58 (95% CI: 0.02, 8.43), and for non-CLL, ERR/Gy was 2.21 (95% CI: 0.05, 7.61). Altogether, 16% of leukemia cases (18% of CLL, 15% of non-CLL) were attributed to radiation exposure.
 Conclusions: Exposure to low doses and to low dose-rates of radiation from post-Chornobyl cleanup work was associated with a significant increase in risk of leukemia, which was statistically consistent with estimates for the Japanese atomic bomb survivors. Based on the primary analysis, we conclude that CLL and non-CLL are both radiosensitive.

Impact of uncertainties in exposure assessment on estimates of thyroid cancer risk among Ukrainian children and adolescents exposed from the chernobyl accident

The 1986 accident at the Chernobyl nuclear power plant remains the most serious nuclear accident in history, and excess thyroid cancers, particularly among those exposed to releases of iodine-131 remain the best-documented sequelae. Failure to take dose-measurement error into account can lead to bias in assessments of dose-response slope. Although risks in the Ukrainian-US thyroid screening study have been previously evaluated, errors in dose assessments have not been addressed hitherto. Dose-response patterns were examined in a thyroid screening prevalence cohort of 13,127 persons aged <18 at the time of the accident who were resident in the most radioactively contaminated regions of Ukraine. We extended earlier analyses in this cohort by adjusting for dose error in the recently developed TD-10 dosimetry. Three methods of statistical correction, via two types of regression calibration, and Monte Carlo maximum-likelihood, were applied to the doses that can be derived from the ratio of thyroid activity to thyroid mass. The two components that make up this ratio have different types of error, Berkson error for thyroid mass and classical error for thyroid activity. The first regression-calibration method yielded estimates of excess odds ratio of 5.78 Gy-1 (95% CI 1.92, 27.04), about 7% higher than estimates unadjusted for dose error. The second regression-calibration method gave an excess odds ratio of 4.78 Gy-1 (95% CI 1.64, 19.69), about 11% lower than unadjusted analysis. The Monte Carlo maximum-likelihood method produced an excess odds ratio of 4.93 Gy-1 (95% CI 1.67, 19.90), about 8% lower than unadjusted analysis. There are borderline-significant (p= 0.101-0.112) indications of downward curvature in the dose response, allowing for which nearly doubled the low-dose linear coefficient. In conclusion, dose-error adjustment has comparatively modest effects on regression parameters, a consequence of the relatively small errors, of a mixture of Berkson and classical form, associated with thyroid dose assessment

Integrated radiation monitoring and interlock system for the LHD deuterium experiments

The Large Helical Device (LHD) successfully started the deuterium experiment in March 2017, in which further plasma performance improvement is envisaged to provide a firm basis for the helical reactor design. Some major upgrades of facilities have been made for safe and productive deuterium experiments. For radiation safety, the tritium removal system, the integrated radiation monitoring system, and the access control system have been newly installed. Each system has new interlock signals that will prevent any unsafe plasma operation or plant condition. Major interlock extensions have been implemented as a part of the integrated radiation monitoring system, which also has an inter-connection to the LHD central operation and control system. The radiation monitoring system RMSAFE (Radiation Monitoring System Applicable to Fusion Experiments) is already operating for monitoring γ(X)-rays in LHD. Some neutron measurements have been additionally applied for the deuterium experiments. The LHD data acquisition system LABCOM can acquire and process 24 h every day continuous data streams. Since γ(X)-ray and neutron measurements require higher availability, the sensors, controllers, data acquisition computers, network connections, and visualization servers have been designed to be duplicated or multiplexed for redundancy. The radiation monitoring displays in the LHD control room have been carefully designed to have excellent visual recognition, and to make users immediately aware of several alerts regarding the dose limits. The radiation safety web pages have been also upgraded to always show both dose rates of γ(X)-rays and neutrons in real time

Detection of Tuberculosis Infection Hotspots Using Activity Spaces Based Spatial Approach in an Urban Tokyo, from 2003 to 2011

Background: Identifying ongoing tuberculosis infection sites is crucial for breaking chains of transmission in tuberculosis-prevalent urban areas. Previous studies have pointed out that detection of local accumulation of tuberculosis patients based on their residential addresses may be limited by a lack of matching between residences and tuberculosis infection sites. This study aimed to identify possible tuberculosis hotspots using TB genotype clustering statuses and a concept of "activity space", a place where patients spend most of their waking hours. We further compared the spatial distribution by different residential statuses and describe urban environmental features of the detected hotspots. Methods: Culture-positive tuberculosis patients notified to Shinjuku city from 2003 to 2011 were enrolled in this case-based cross-sectional study, and their demographic and clinical information, TB genotype clustering statuses, and activity space were collected. Spatial statistics (Global Moran\u27s I and Getis-Ord Gi? statistics) identified significant hotspots in 152 census tracts, and urban environmental features and tuberculosis patients\u27 characteristics in these hotspots were assessed. Results: Of the enrolled 643 culture-positive tuberculosis patients, 416 (64.2%) were general inhabitants, 42 (6.5%) were foreign-born people, and 184 were homeless people (28.6%). The percentage of overall genotype clustering was 43.7%. Genotype-clustered general inhabitants and homeless people formed significant hotspots around a major railway station, whereas the non-clustered general inhabitants formed no hotspots. This suggested the detected hotspots of activity spaces may reflect ongoing tuberculosis transmission sites and were characterized by smaller residential floor size and a higher proportion of nonworking households. Conclusions: Activity space-based spatial analysis suggested possible TB transmission sites around the major railway station and it can assist in further comprehension of TB transmission dynamics in an urban setting in Japan

Updating the approaches to define susceptibility and resistance to anti-tuberculosis agents: implications for diagnosis and treatment

11 páginas, 2 figuras, 1 tablaInappropriately high breakpoints have resulted in systematic false-susceptible AST results to anti-TB drugs. MIC, PK/PD and clinical outcome data should be combined when setting breakpoints to minimise the emergence and spread of antimicrobial resistance.I. Comas was supported by PID2019-104477RB-I00 from the Spanish Science Ministry and by ERC (CoG 101001038)Peer reviewe