Background
The amount of postoperative weight loss after bariatric surgery varies interindividually. The quality of the pre- and postoperative body composition is an important predictor of success. ...The aim of this study was to investigate the role of preoperative handgrip strength and phase angle (PhA) as predictors of sustained postoperative weight loss in order to assess the influence of body composition on the postoperative outcome after bariatric surgery.
Method
In a prospective cohort study, bioelectrical impedance and follow-up data of 198 patients after laparoscopic sleeve gastrectomy (SG;
n
= 68) and Roux-en-Y gastric bypass (GB;
n
= 130) were analyzed for a period of 36 months postoperatively.
Results
The mean preoperative handgrip strength (31.48 kg, SD 9.97) correlates significantly with the postoperative body composition up to 24 months after surgery. Preoperative PhA, gender, size, and body weight influenced postoperative weight loss significantly. A significant correlation between preoperative PhA (mean 6.18°, SD 0.89°) and total weight loss (%TWL) was observed up to 3 months after SG (
r
= 0.31444,
p
= 0.0218) and up to 12 months after GB (
r
= 0.19184,
p
= 0.0467). The optimum cutoff for the prediction of a response of less than 50% excess weight loss was a preoperative PhA of 6.0°.
Conclusions
The preoperative handgrip strength confirmed its suitability for use as a predictor of postoperative body composition, whereas the preoperative PhA predicts postoperative weight loss after bariatric surgery. Further research is necessary to identify the role of these parameters for preconditioning.
Nanocrystals of apatitic calcium phosphate impart the organic-inorganic nanocomposite in bone with favorable mechanical properties. So far, the factors preventing crystal growth beyond the favorable ...thickness of ca. 3 nm have not been identified. Here we show that the apatite surfaces are studded with strongly bound citrate molecules, whose signals have been identified unambiguously by multinuclear magnetic resonance (NMR) analysis. NMR reveals that bound citrate accounts for 5.5 wt% of the organic matter in bone and covers apatite at a density of about 1 molecule per (2 nm)², with its three carboxylate groups at distances of 0.3 to 0.45 nm from the apatite surface. Bound citrate is highly conserved, being found in fish, avian, and mammalian bone, which indicates its critical role in interfering with crystal thickening and stabilizing the apatite nanocrystals in bone.
Enhancement of thermopower is achieved by doping the narrow‐band semiconductor Ag6.52Sb6.52Ge36.96Te50 (acronym TAGS‐85), one of the best p‐type thermoelectric materials, with 1 or 2% of the rare ...earth dysprosium (Dy). Evidence for the incorporation of Dy into the lattice is provided by X‐ray diffraction and increased orientation‐dependent local fields detected by 125Te NMR spectroscopy. Since Dy has a stable electronic configuration, the enhancement cannot be attributed to 4f‐electron states formed near the Fermi level. It is likely that the enhancement is due to a small reduction in the carrier concentration, detected by 125Te NMR spectroscopy, but mostly due to energy filtering of the carriers by potential barriers formed in the lattice by Dy, which has large both atomic size and localized magnetic moment. The interplay between the thermopower, the electrical resistivity, and the thermal conductivity of TAGS‐85 doped with Dy results in an enhancement of the power factor (PF) and the thermoelectric figure of merit (ZT) at 730 K, from PF = 28 μW cm−1 K−2 and ZT ≤ 1.3 in TAGS‐85 to PF = 35 μW cm−1 K−2 and ZT ≥ 1.5 in TAGS‐85 doped with 1 or 2% Dy for Ge. This makes TAGS‐85 doped with Dy a promising material for thermoelectric power generation.
The doping of tellurium‐antimony‐ germanium‐silver (TAGS‐85) alloy with Dy, a rare‐earth element with large atomic size and localized magnetic moment, enhances the thermopower, the power factor, and the thermoelectric figure of merit significantly. This may be attributed partially to a reduction in carrier concentration and partially to energy filtering of the carriers by potential barriers associated with the Dy.
•Integration of CNN and gated RNN over multiple scales•Introduction of normalized focal loss for momentum based optimizers.•Provision of insights on how our extensions affect training and ...inference.•Quantitative evaluation using a wide spectrum of 2D and 3D real microscopy image data.
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Cell segmentation in microscopy images is a common and challenging task. In recent years, deep neural networks achieved remarkable improvements in the field of computer vision. The dominant paradigm in segmentation is using convolutional neural networks, less common are recurrent neural networks. In this work, we propose a new deep learning method for cell segmentation, which integrates convolutional neural networks and gated recurrent neural networks over multiple image scales to exploit the strength of both types of networks. To increase the robustness of the training and improve segmentation, we introduce a novel focal loss function. We also present a distributed scheme for optimized training of the integrated neural network. We applied our proposed method to challenging data of glioblastoma cell nuclei and performed a quantitative comparison with state-of-the-art methods. Insights on how our extensions affect training and inference are also provided. Moreover, we benchmarked our method using a wide spectrum of all 22 real microscopy datasets of the Cell Tracking Challenge.
Past work suggests that perceived reciprocity in social relationships declines with age. Although positive associations between perceived reciprocity and relationship satisfaction have been ...documented, relationship satisfaction seems to remain relatively stable over the life-span. Addressing this seemingly contradictory pattern of findings, we predicted that perceived reciprocity may become less important to relationship satisfaction with age and that this association differs across various relationship categories (i.e., spousal, communal, and exchange relationships). We tested these predictions applying multilevel models to cross-sectional and longitudinal data of middle-aged and older adults from the Interdisciplinary Longitudinal Study of Aging (ILSE). Consistent with past work, perceived reciprocity was lower in older than middle-aged adults and declined over time, while relationship satisfaction did not differ between age groups and increased over time. Inconsistent with our prediction, the association between perceived reciprocity and relationship satisfaction was stronger in older than middle-aged adults in our cross-sectional analyses. By contrast, the longitudinal analyses that were based on only older adults were consistent with our prediction: the association between perceived reciprocity and relationship satisfaction decreased over time. Additionally, the association between perceived reciprocity and relationship satisfaction differed between relationship categories, being particularly strong in spousal relationships and less in communal and exchange relationships. In general, our results suggest that both, age and relationship category, need to be considered when investigating perceived reciprocity and relationship satisfaction from an adult life-span perspective.
Doping of TAGS‐85 with 1 at% Ce or Yb forms a dilute magnetic semiconductor system with non‐interacting localized magnetic moments that obey the Curie law. X‐ray diffraction patterns and slight ...broadening in 125Te NMR, attributed to paramagnetic effects, suggest that Ce and Yb atoms are incorporated into the lattice. 125Te NMR spin‐lattice relaxation and Hall effect show similar hole concentrations of ≈1021 cm−3. At 700 K, the electric conductivity of the Ce‐ and Yb‐doped samples is similar to that of neat TAGS‐85, while the thermal conductivity and the Seebeck coefficient are larger by 6% and 16%, respectively. Possible mechanisms responsible for the observed increase in thermopower may include i) formation of resonance states near the Fermi level and ii) carrier scattering by lattice distortions and/or by paramagnetic ions. Due to the increase in the Seebeck coefficient up to 205 μV K−1, the thermoelectric power factor of Ce‐ and Yb‐doped samples reaches 36 μW cm−1 K−2, which is larger than that measured for neat TAGS‐85, 27 μW cm−1 K−2. The increase in the Seebeck coefficient overcomes the increase in the thermal conductivity, resulting in a total increase of the figure of merit by ≈25% at 700 K compared to that observed for neat TAGS‐85.
Doping of TAGS‐85 (Ag6.52Sb6.52Ge36.96Te50.00), a well‐known thermoelectric material with 1 at% Ce or Yb, yields a dilute magnetic semiconductor system. This system has non‐interacting localized magnetic moments and an enhanced thermoelectric power factor and figure of merit.
Automatic segmentation and centerline extraction of retinal blood vessels from fundus image data is crucial for early detection of retinal diseases. We have developed a novel deep learning method for ...segmentation and centerline extraction of retinal blood vessels which is based on the Capsule network in combination with the Inception architecture. Compared to state-of-the-art deep convolutional neural networks, our method has much fewer parameters due to its shallow architecture and generalizes well without using data augmentation. We performed a quantitative evaluation using the DRIVE dataset for both vessel segmentation and centerline extraction. Our method achieved state-of-the-art performance for vessel segmentation and outperformed existing methods for centerline extraction.
South Africa has the largest share of people living with HIV in the world and this population is ageing. The social context in which people seek HIV care is often ignored. Apart from clinical ...interventions, socio-behavioural factors impact successful HIV care outcomes for older adults living with HIV. We use cross-sectional data linked with demographic household surveillance data, consisting of HIV positive adults aged above 40, to identify socio-behavioural predictors of a detectable viral load. Older adults were more likely to have a detectable viral load if they did not disclose their HIV positive status to close family members (aOR 2.56, 95% CI 1.89-3.46), resided in the poorest households (aOR 1.98, 95% CI 1.23-3.18), or were not taking medications other than ART (aOR 1.83, 95% CI 1.02-1.99) likely to have a detectable. Clinical interventions in HIV care must be supported by understanding the socio-behavioural barriers that occur outside the health facility. The importance of community health care workers in bridging this gap may offer more optimum outcomes for older adults ageing with HIV.
•Globally optimal model-based approach for cell nuclei segmentation.•Joint exploitation of shape and intensity information using elliptical models.•Models fitted directly to image intensities by ...second-order convex optimization.•Global multi-object energy minimization solved by min-weight set-cover.•Quantitative study of efficiency, robustness, and accuracy using five cell types.
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Accurate and efficient segmentation of cell nuclei in fluorescence microscopy images plays a key role in many biological studies. Besides coping with image noise and other imaging artifacts, the separation of touching and partially overlapping cell nuclei is a major challenge. To address this, we introduce a globally optimal model-based approach for cell nuclei segmentation which jointly exploits shape and intensity information. Our approach is based on implicitly parameterized shape models, and we propose single-object and multi-object schemes. In the single-object case, the used shape parameterization leads to convex energies which can be directly minimized without requiring approximation. The multi-object scheme is based on multiple collaborating shapes and has the advantage that prior detection of individual cell nuclei is not needed. This scheme performs joint segmentation and cluster splitting. We describe an energy minimization scheme which converges close to global optima and exploits convex optimization such that our approach does not depend on the initialization nor suffers from local energy minima. The proposed approach is robust and computationally efficient. In contrast, previous shape-based approaches for cell segmentation either are computationally expensive, not globally optimal, or do not jointly exploit shape and intensity information. We successfully applied our approach to fluorescence microscopy images of five different cell types and performed a quantitative comparison with previous methods.
Large-scale soil application of biochar may enhance soil fertility, increasing crop production for the growing human population, while also sequestering atmospheric carbon. But reaching these ...beneficial outcomes requires an understanding of the relationships among biochar’s structure, stability, and contribution to soil fertility. Using quantitative 13C nuclear magnetic resonance (NMR) spectroscopy, we show that Terra Preta soils (fertile anthropogenic dark earths in Amazonia that were enriched with char >800 years ago) consist predominantly of char residues composed of ∼6 fused aromatic rings substituted by COO– groups that significantly increase the soils’ cation-exchange capacity and thus the retention of plant nutrients. We also show that highly productive, grassland-derived soils in the U.S. (Mollisols) contain char (generated by presettlement fires) that is structurally comparable to char in the Terra Preta soils and much more abundant than previously thought (∼40–50% of organic C). Our findings indicate that these oxidized char residues represent a particularly stable, abundant, and fertility-enhancing form of soil organic matter.
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