696 research outputs found
Frequency and resistance pattern of extended spectrum beta lactamase producing Escherichia coli in clinical specimen of Alzahra hospital in Isfahan, Iran, 2007
چکیده: زمینه و هدف: اشرشیاکلی تولیـــد کننده بتالاکتامازهای وسیع الطیف (ESBL) به علت مقاومت به آنتی بیوتیک های مختلــف، مشکلات درمانی زیادی را ایجاد کرده است. هدف از این مطالعه تعیین شیوع اشرشیاکلی های تولید کننده ESBL و الگوهای مقاومت آنتی بیوتیکی آنها بوده است. روش بررسی: در این مطالعه توصیفی – تحلیلی 278 نمونه کلینیکی اشرشیاکلی از بیمارستان الزهرا(س) اصفهان جمع آوری و با کشت در محیط های انتخابی و تست های بیوشیمیایی تایید شد. برای تشخیص ایزوله های ESBL از روش استفاده از دو دیسک آموکسی سیلین به علاوه کلاولانیک اسید و سفوتاکسیم و در آزمون تاییدی (طبق پیشنهادهای NCCLS) حساسیت نمونه ها توسط روش دیسک دیفیوژن به 10 آنتی بیوتیک تعیین گردید. داده ها با استفاده از آزمون های آماری کای دو تجزیه و تحلیل شد. یافته ها: از 278 نمونه جدا شده 150 نمونه (9/53) تولید کننده ESBL بودند. همه سوش ها به ایمی پنم و مروپنم حساس بودند. در مقایسه مقاومت آنتی بیوتیکی بین سوش های تولید کننده ESBL و سوش هایی که قادر به تولید ESBL نبودند، اختلاف معنی داری در مورد کینولون ها و آمینوگلیکوزیدها مشاهده شد (05/0
Combining Physical Simulators and Object-Based Networks for Control
Physics engines play an important role in robot planning and control;
however, many real-world control problems involve complex contact dynamics that
cannot be characterized analytically. Most physics engines therefore employ .
approximations that lead to a loss in precision. In this paper, we propose a
hybrid dynamics model, simulator-augmented interaction networks (SAIN),
combining a physics engine with an object-based neural network for dynamics
modeling. Compared with existing models that are purely analytical or purely
data-driven, our hybrid model captures the dynamics of interacting objects in a
more accurate and data-efficient manner.Experiments both in simulation and on a
real robot suggest that it also leads to better performance when used in
complex control tasks. Finally, we show that our model generalizes to novel
environments with varying object shapes and materials.Comment: ICRA 2019; Project page: http://sain.csail.mit.ed
Statistical properties of a localization-delocalization transition induced by correlated disorder
The exact probability distributions of the resistance, the conductance and
the transmission are calculated for the one-dimensional Anderson model with
long-range correlated off-diagonal disorder at E=0. It is proved that despite
of the Anderson transition in 3D, the functional form of the resistance (and
its related variables) distribution function does not change when there exists
a Metal-Insulator transition induced by correlation between disorders.
Furthermore, we derive analytically all statistical moments of the resistance,
the transmission and the Lyapunov Exponent. The growth rate of the average and
typical resistance decreases when the Hurst exponent tends to its critical
value () from the insulating regime.
In the metallic regime , the distributions become independent of
size. Therefore, the resistance and the transmission fluctuations do not
diverge with system size in the thermodynamic limit
Protection of mice by a λ-based therapeutic vaccine against cancer associated with human papillomavirus type 16
Objective: Human papillomavirus (HPV) oncoproteins (i.e. E6 and E7) are constitutively expressed in cervical cancer cells. The proteins are ideal targets to be used for developing therapeutic vaccines against existing HPV-associated carcinomas. To date, whole bacteriophage ('phage')-λ particles, rather than purified 'naked' DNA, have been described as highly efficient delivery vehicles for a DNA vaccine. Methods: In this study, a safe and efficient λ-based therapeutic cancer vaccine, recombinant λ-ZAP E7 phage, was developed by inserting a HPV16 E7 gene into the Lambda ZAP® cytomegalovirus vector. λ-ZAP E7 phages were employed to immunize mice against the E7-expressing murine tumor cell line (TC-1), which is used as a tumor model in an H-2b murine system. Results: The tumor-bearing mice indicated a significant inhibition of tumor growth after 3 injections of 2 × 1012 particles of recombinant phages. Released lactate dehydrogenase, interferon-γ and granzyme B from spleen cells and lymphocyte proliferation of spleen cells, which all demonstrate the enhancement of cell-mediated immunity, suggested the phages could be a potent gene delivery system in animal models. Conclusion: Our results suggest the recombinant phages can be used as effective biological tools for inducing E7-specific protective immune responses. Hence, the study introduces a possible therapeutic strategy against cervical cancer and other HPV-related neoplasia. Copyright © 2010 S. Karger AG, Basel
Особливості розвитку освітнього потенціалу України в умовах глобалізації
BACKGROUND: Recommended screening to identify children at risk for diabetes and its precursors impaired glucose tolerance (IGT) and insulin resistance (IR) is fasted plasma glucose (FPG). This study evaluates the added value of fasted plasma insulin (FPI). METHODS: This study analyzed routinely collected data of an oral glucose tolerance test (OGTT) of 311 obese children (age 10.8 ± 3.2 years). Diabetes and IGT were defined according to the American Diabetes Association criteria, IR as homeostasis model assessment (HOMA)-IR ≥3.4. RESULTS: Cases diagnosed with an OGTT if FPG ≥5.6 mmol/L, compared with an OGTT performed if FPG ≥5.6 mmol/L or HOMA-IR ≥3.4, were, respectively, 4 (80%) versus 5 (100%) with diabetes, 7 (28%) versus 16 (64%) with IGT, and 0 (0%) versus 93 (100%) with IR. CONCLUSIONS: Screening with FPG and FPI has equal burden compared with screening with FPG alone, identifies all patients with diabetes, and identifies more patients with precursors of diabetes
The battle of the sexes starts in the oviduct: modulation of oviductal transcriptome by X and Y-bearing spermatozoa
BACKGROUND:Sex allocation of offspring in mammals is usually considered as a matter of chance, being dependent on whether an X- or a Y-chromosome-bearing spermatozoon reaches the oocyte first. Here we investigated the alternative possibility, namely that the oviducts can recognise X- and Y- spermatozoa, and may thus be able to bias the offspring sex ratio.
RESULTS:By introducing X- or Y-sperm populations into the two separate oviducts of single female pigs using bilateral laparoscopic insemination we found that the spermatozoa did indeed elicit sex-specific transcriptomic responses. Microarray analysis revealed that 501 were consistently altered (P-value <0.05) in the oviduct in the presence of Y-chromosome-bearing spermatozoa compared to the presence of X-chromosome-bearing spermatozoa. From these 501 transcripts, 271 transcripts (54.1%) were down-regulated and 230 transcripts (45.9%) were up-regulated when the Y- chromosome-bearing spermatozoa was present in the oviduct. Our data showed that local immune responses specific to each sperm type were elicited within the oviduct. In addition, either type of spermatozoa elicits sex-specific signal transduction signalling by oviductal cells.
CONCLUSIONS:Our data suggest that the oviduct functions as a biological sensor that screens the spermatozoon, and then responds by modifying the oviductal environment. We hypothesize that there might exist a gender biasing mechanism controlled by the female
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Irisin Levels Are Lower in Young Amenorrheic Athletes Compared with Eumenorrheic Athletes and Non-Athletes and Are Associated with Bone Density and Strength Estimates
Irisin and FGF21 are novel hormones implicated in the “browning” of white fat, thermogenesis, and energy homeostasis. However, there are no data regarding these hormones in amenorrheic athletes (AA) (a chronic energy deficit state) compared with eumenorrheic athletes (EA) and non-athletes. We hypothesized that irisin and FGF21 would be low in AA, an adaptive response to low energy stores. Furthermore, because (i) brown fat has positive effects on bone, and (ii) irisin and FGF21 may directly impact bone, we hypothesized that bone density, structure and strength would be positively associated with these hormones in athletes and non-athletes. To test our hypotheses, we studied 85 females, 14–21 years [38 AA, 24 EA and 23 non-athletes (NA)]. Fasting serum irisin and FGF21 were measured. Body composition and bone density were assessed using dual energy X-ray absorptiometry, bone microarchitecture using high resolution peripheral quantitative CT, strength estimates using finite element analysis, resting energy expenditure (REE) using indirect calorimetry and time spent exercising/week by history. Subjects did not differ for pubertal stage. Fat mass was lowest in AA. AA had lower irisin and FGF21 than EA and NA, even after controlling for fat and lean mass. Across subjects, irisin was positively associated with REE and bone density Z-scores, volumetric bone mineral density (total and trabecular), stiffness and failure load. FGF21 was negatively associated with hours/week of exercise and cortical porosity, and positively with fat mass and cortical volumetric bone density. Associations of irisin (but not FGF21) with bone parameters persisted after controlling for potential confounders. In conclusion, irisin and FGF21 are low in AA, and irisin (but not FGF21) is independently associated with bone density and strength in athletes
Cancer - Cell survival guide
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62618/1/431035a.pd
Diversity of actin architecture in human osteoclasts: Network of curved and branched actin supporting cell shape and intercellular micrometer level tubes
Osteoclasts are multinucleated bone-resorbing cells with a dynamic actin
cytoskeleton. Osteoclasts are derived from circulating mononuclear
precursors. Confocal and stimulated emission depletion (STED)
super-resolution microscopy was used to investigate peripheral
blood-derived human osteoclasts cultured on glass surfaces. STED and
confocal microscopy demonstrated that the actin was curved and branched,
for instance, in the vicinity of membrane ruffles. The overall
architecture of the curved actin network extended from the podosomes to
the top of the cell. The other novel finding was that a micrometer-level
tube containing actin bridged the osteoclasts well above the level of
the culture glass. The actin filaments of the tubes originated from the
network of curved actin often surrounding a group of nuclei.
Furthermore, nuclei were occasionally located inside the tubes. Our
findings demonstrated the accumulation of c-Src, cortactin, cofilin, and
actin around nuclei suggesting their role in nuclear processes such as
the locomotion of nuclei. ARP2/3 labeling was abundant at the substratum
level of osteoclasts and in the branched actin network, where it
localized to the branching points. We speculate that the
actin-containing tubes of osteoclasts may provide a means of
transportation of nuclei, e.g., during the fusion of osteoclasts. These
novel findings can pave the way for future studies aiming at the
elucidation of the differentiation of multinucleated osteoclasts.</p
In vitro model of bone to facilitate measurement of adhesion forces and super-resolution imaging of osteoclasts
To elucidate processes in the osteoclastic bone resorption, visualise resorption and related actin reorganisation, a combination of imaging technologies and an applicable in vitro model is needed. Nanosized bone powder from matching species is deposited on any biocompatible surface in order to form a thin, translucent, smooth and elastic representation of injured bone. Osteoclasts cultured on the layer expressed matching morphology to ones cultured on sawed cortical bone slices. Resorption pits were easily identified by reflectance microscopy. The coating allowed actin structures on the bone interface to be visualised with super-resolution microscopy along with a detailed interlinked actin networks and actin branching in conjunction with V-ATPase, dynamin and Arp2/3 at actin patches. Furthermore, we measured the timescale of an adaptive osteoclast adhesion to bone by force spectroscopy experiments on live osteoclasts with bone-coated AFM cantilevers. Utilising the in vitro model and the advanced imaging technologies we localised immunofluorescence signals in respect to bone with high precision and detected resorption at its early stages. Put together, our data supports a cyclic model for resorption in human osteoclasts.</p
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