Room temperature operation of germanium-silicon single-photon avalanche diode.

The ability to detect single photons has led to the advancement of numerous research fields1-11. Although various types of single-photon detector have been developed12, because of two main factors-that is, (1) the need for operating at cryogenic temperature13,14 and (2) the incompatibility with complementary metal-oxide-semiconductor (CMOS) fabrication processes15,16-so far, to our knowledge, only Si-based single-photon avalanche diode (SPAD)17,18 has gained mainstream success and has been used in consumer electronics. With the growing demand to shift the operation wavelength from near-infrared to short-wavelength infrared (SWIR) for better safety and performance19-21, an alternative solution is required because Si has negligible optical absorption for wavelengths beyond 1 µm. Here we report a CMOS-compatible, high-performing germanium-silicon SPAD operated at room temperature, featuring a noise-equivalent power improvement over the previous Ge-based SPADs22-28 by 2-3.5 orders of magnitude. Key parameters such as dark count rate, single-photon detection probability at 1,310 nm, timing jitter, after-pulsing characteristic time and after-pulsing probability are, respectively, measured as 19 kHz µm-2, 12%, 188 ps, ~90 ns and <1%, with a low breakdown voltage of 10.26 V and a small excess bias of 0.75 V. Three-dimensional point-cloud images are captured with direct time-of-flight technique as proof of concept. This work paves the way towards using single-photon-sensitive SWIR sensors, imagers and photonic integrated circuits in everyday life.

Implementation difficulties and solutions for a smart-clothes assisted home nursing care program for older adults with dementia or recovering from hip fracture.

BACKGROUND: Wearable devices have the advantage of always being with individuals, enabling easy detection of their movements. Smart clothing can provide feedback to family caregivers of older adults with disabilities who require in-home care. METHODS: This study describes the process of setting up a smart technology-assisted (STA) home-nursing care program, the difficulties encountered, and strategies applied to improve the program. The STA program utilized a smart-vest, designed specifically for older persons with dementia or recovering from hip-fracture surgery. The smart-vest facilitated nurses' and family caregivers' detection of a care receiver's movements via a remote-monitoring system. Movements included getting up at night, time spent in the bathroom, duration of daytime immobility, leaving the house, and daily activity. Twelve caregivers of older adults and their care receiver participated; care receivers included persons recovering from hip fracture (n = 5) and persons living with dementia (n = 7). Data about installation of the individual STA in-home systems, monitoring, and technical difficulties encountered were obtained from researchers' reports. Qualitative data about the caregivers' and care receivers' use of the system were obtained from homecare nurses' reports, which were explored with thematic analysis. RESULTS: Compiled reports from the research team identified three areas of difficulty with the system: incompatibility with the home environment, which caused extra hours of manpower and added to the cost of set-up and maintenance; interruptions in data transmissions, due to system malfunctions; and inaccuracies in data transmissions, due to sensors on the smart-vest. These difficulties contributed to frustration experienced by caregivers and care receivers. CONCLUSIONS: The difficulties encountered impeded implementation of the STA home nursing care. Each of these difficulties had their own unique problems and strategies to resolve them. Our findings can provide a reference for future implementation of similar smart-home systems, which could facilitate ease-of-use for family caregivers.

Design of a Completely Vertical, Polarization-Independent Two-Dimensional Grating Coupler with High Coupling Efficiency.

An efficient optical coupler to transfer the signal between an optical fiber and a silicon waveguide is essential for realizing the applications of silicon photonic integrated circuits such as optical communication and optical sensing. In this paper, we numerically demonstrate a two-dimensional grating coupler based on a silicon-on-insulator platform to obtain completely vertical and polarization-independent couplings, which potentially ease the difficulty of packaging and measurement of photonic integrated circuits. To mitigate the coupling loss induced by the second-order diffraction, two corner mirrors are respectively placed at the two orthogonal ends of the two-dimensional grating coupler to create appropriate interference conditions. Partial single-etch is assumed to form an asymmetric grating to obtain high directionalities without a bottom mirror. The two-dimensional grating coupler is optimized and verified with finite-difference time-domain simulations, achieving a high coupling efficiency of -1.53 dB and a low polarization-dependent loss of 0.015 dB when coupling to a standard single-mode fiber at approximately 1310 nm wavelength.

Clinical Implications of HBV PreS/S Mutations and the Effects of PreS2 Deletion on Mitochondria, Liver Fibrosis, and Cancer Development.

BACKGROUND AND AIMS: PreS mutants of HBV have been reported to be associated with HCC. We conducted a longitudinal study of the role of HBV preS mutations in the development of HCC, particularly in patients with chronic hepatitis B (CHB) having low HBV DNA or alanine aminotransferase (ALT) levels, and investigated the effects of secretion-defective preS2 deletion mutant (preS2ΔMT) on hepatocyte damage in vitro and liver fibrosis in vivo. APPROACH AND RESULTS: Association of preS mutations with HCC in 343 patients with CHB was evaluated by a retrospective case-control follow-up study. Effects of preS2ΔMT on HBsAg retention, endoplasmic reticulum (ER) stress, calcium accumulation, mitochondrial dysfunction, and liver fibrosis were examined. Multivariate analysis revealed a significant association of preS mutations with HCC (HR, 3.210; 95% CI, 1.072-9.613; P = 0.037) including cases with low HBV DNA or ALT levels (HR, 2.790; 95% CI, 1.133-6.873; P = 0.026). Antiviral therapy reduced HCC risk, including cases with preS mutations. PreS2ΔMT expression promoted HBsAg retention in the ER and unfolded protein response (UPR). Transmission electron microscopic examination, MitoTracker staining, real-time ATP assay, and calcium staining of preS2ΔMT-expressing cells revealed aberrant ER and mitochondrial ultrastructure, reduction of mitochondrial membrane potential and ATP production, and calcium overload. Serum HBV secretion levels were ~100-fold lower in preS2ΔMT-infected humanized Fah-/-/ Rag2-/-/Il2rg-/- triple knockout mice than in wild-type HBV-infected mice. PreS2ΔMT-infected mice displayed up-regulation of UPR and caspase-3 and enhanced liver fibrosis. CONCLUSIONS: PreS mutations were significantly associated with HCC development in patients with CHB, including those with low HBV DNA or ALT levels. Antiviral therapy reduced HCC occurrence in patients with CHB, including those with preS mutations. Intracellular accumulation of mutated HBsAg induced or promoted ER stress, calcium overload, mitochondrial dysfunction, impaired energy metabolism, liver fibrosis, and HCC.

Smart clothes-assisted home-nursing care program for family caregivers of older persons with dementia and hip fracture: a mixed-methods study.

BACKGROUND: The purpose of this preliminary study was to explore whether a smart clothes-assisted home-nursing care program could benefit family caregivers and their care recipients. METHODS: Family caregivers in charge of a care recipient's living situation participated in this convergent parallel, mixed methods study. We recruited older persons with dementia (n = 7) and those discharged following hip-fracture surgery (n = 6) from neurological clinics and surgical wards of a medical center, respectively, along with their family caregivers: three spouses, eight sons, one daughter, and one daughter-in-law. Care recipients were asked to wear a smart vest at least 4 days/week for 6 months, which contained a coin-size monitor hidden in an inner pocket. Sensors installed in bedrooms and living areas received signals from the smart clothing, which were transmitted to a mobile phone app of homecare nurses, who provided caregivers with transmitted information regarding activities, emergency situations and suggestions for caregiving activities. Outcomes included changes from baseline in caregivers' preparedness and depressive symptoms collected at 1- and 3-months, which were analyzed with Friedman's non-parametric test of repeated measures with post-hoc analysis. Transcripts of face-to-face semi-structured interview data about caregivers' experiences were analyzed to identify descriptive, interpretative, and pattern codes. RESULTS: Preparedness did not change from baseline at either 1- or 3-months for family caregivers of persons with dementia. However, depressive symptoms decreased significantly at 1-month and 3-months compared with baseline, but not between 1-months and 3-months. Analysis of the interview data revealed the smart clothes program increased family caregivers' knowledge of the care recipient's situation and condition, informed healthcare providers of the care recipient's physical health and cognitive status, helped homecare nurses provide timely interventions, balanced the care recipient's exercise and safety, motivated recipients to exercise, helped family caregivers balance work and caregiving, and provided guidance for caregiving activities. CONCLUSIONS: Experiences with the smart clothes-assisted home-nursing care program directly benefited family caregivers, which provided indirect benefits to the care recipients due to the timely interventions and caregiving guidance from homecare nurses. These benefits suggest a smart-clothes-assisted program might be beneficial for all family caregivers.

Experiences of family caregivers of persons living with dementia with and without a smart- clothes assisted home nursing program during the heightened COVID-19 alert.

BACKGROUND: The COVID-19 pandemic has required restrictions of daily activities, which has been found to impact the lives of persons living with dementia (PLWDs) and their family caregivers, who have multiple care demands. The lack of relevant studies in Taiwan emphasized the need to explore the experiences of family caregivers of older PLWDs faced with the intensified restrictions to control the spread of COVID-19, and the impact of the availability of a smart-clothes home nursing program. METHODS: This qualitative study used semi-structured interviews with family caregivers of older PLWDs. Participants were recruited from dementia clinics of a medical center in northern Taiwan from a subset of a sample from a larger study on smart-clothes assisted home nursing care. A total of 12 family caregivers who participated in the original study were interviewed during the follow-up period; seven family caregivers of a PLWD wearing a smart-vest, which transmitted information to a home care nurse; five caregivers of a PLWD not wearing a smart-vest. Interviews were conducted by telephone because the conditions of the pandemic prevented face-to-face interviews. Recorded interviews were transcribed and analyzed using content analysis. RESULTS: Interview data showed family caregivers' felt the care recipient's health was compromised and functional conditions intensified as Covid-19-related pandemic restrictions increased. Specific concerns included a lack social interactions, decreased daily activity levels, loss of interest and lack of motivation for activities, increased mood and behavioral problems, a decline in physical function and an increase in health problems. Family caregivers were also impacted by these restrictions, with significant increases in severity of caregiver role strain, including feeling trapped, a lack of in-home support, profound powerlessness, and worries about the PLWD contracting the coronavirus. The smart-clothes assisted home nursing care program offered supplementary support to family caregivers by providing on-time interactions, helping them manage health problems, enhancing predictability of the care recipient's behaviors, and providing caregivers with emotional support. CONCLUSIONS: The findings of this study support alternative care such as implementation of technology-assisted home health services to meet caregiver needs to facilitate family caregiving of PLWDs during the necessary restrictions in activities implemented during the COVID-19 pandemic. TRIAL REGISTRATION: ClinicalTrials.gov Protocol Record NCT05063045.

Effectiveness of end-stage renal disease communication skills training for healthcare personnel: a single-center, single-blind, randomized study.

BACKGROUND: Given that the consequences of treatment decisions for end-stage renal disease (ESRD) patients are long-term and significant, good communication skills are indispensable for health care personnel (HCP) working in nephrology. However, HCP have busy schedules that make participation in face-to-face courses difficult. Thus, online curricula are a rising trend in medical education. This study aims to examine the effectiveness of online ESRD communication skills training (CST) concerning the truth-telling confidence and shared decision-making (SDM) ability of HCP. METHODS: For this single-center, single-blind study, 91 participants (nephrologists and nephrology nurses) were randomly assigned to two groups, the intervention group (IG) (n = 45) or the control group (CG) (n = 46), with the IG participating in ESRD CST and the CG receiving regular in-service training. Truth-telling confidence and SDM ability were measured before (T0), 2 weeks after (T1), and 4 weeks after (T2) the intervention. Group differences over the study period were analyzed by generalized estimating equations. RESULTS: IG participants exhibited significantly higher truth-telling confidence at T1 than did CG participants (t = 2.833, P = .006, Cohen's d = 0.59), while there were no significant intergroup differences in the confidence levels of participants in the two groups at T0 and T2. Concerning SDM ability, there were no significant intergroup differences at any of the three time points. However, IG participants had high levels of satisfaction (n = 43, 95%) and were willing to recommend ESRD CST to others (n = 41, 91.1%). CONCLUSIONS: ESRD CST enhanced short-term truth-telling confidence, though it is unclear whether this was due to CST content or the online delivery. However, during pandemics, when face-to-face training is unsuitable, online CST is an indispensable tool. Future CST intervention studies should carefully design interactive modules and control for method of instruction.

Heat sink effect of underwater polypectomy in a porcine colon model.

BACKGROUND: Underwater polypectomy without the need for submucosal injection has been reported. A heat-sink effect by immersing the polyp in water was proposed but no such experiment has been performed to support the claim. We compared the temperature rise on the serosal side during polypectomy between air- and water-filled colon. METHOD: Freshly harvested porcine colons were placed in a metal tray with cautery electrode pad attached to its bottom. An upper endoscope was used with a cap and a rubber band mounted to the distal end. A mucosal site was randomly selected and identified on its serosal surface with a marker while suction was applied. Suction was applied again and a ligation band was applied to create a polyp. A cautery snare grasped the artificial polyp just below the band. An assistant placed the tip of a thermometer at the marked site on the serosal surface to record the baseline temperature before cautery and the highest temperature during polypectomy. Seven polypectomies in air and underwater were performed. RESULTS: Mean (standard deviation) baseline temperature were 23.3 (0.6) °C and 23.4 (0.6) °C in the air and water groups, respectively. The maximum rise in temperature during polypectomy was 6.1 (4.5) °C and 1.4 (1.0) °C in the air and water groups, respectively (P = 0.004). CONCLUSIONS: The maximum temperature rise during polypectomy was significantly less when polypectomy was performed underwater, supporting the hypothesis that a heat-sink effect does exist during underwater polypectomy.

Association of diabetes, education level, and care dependency with use of temporary vascular access in patients with chronic kidney disease.

OBJECTIVE: Temporary vascular access (TVA) is frequently used during the first dialysis in patients with chronic kidney disease (CKD), and it is associated with an increased risk of infection, central vein stenosis, and mortality. Here, factors associated with TVA in patients with CKD were explored. METHODS: This study included patients in a single-center CKD care program who initiated long-term renal replacement therapy. The primary outcome was TVA use at first dialysis. Factors possibly associated with TVA use were analyzed using Cox regression. RESULTS: Temporary vascular access was used in 53.2% of the patients at first dialysis. In total, 73.2% (n = 865) and 26.8% (n = 317) of the patients were on hemodialysis and peritoneal dialysis, respectively. Multivariate Cox regression analysis showed that TVA use in patients with CKD was associated with diabetes (hazard ratio [HR] 1.52, 95% confidence interval [CI] 1.28-1.81, p < 0.001), lower albumin (HR 0.82, 95% CI 0.75-0.91, p < 0.001), lower education level (HR 0.75, 95% CI 0.56-1.00, p = 0.055), and total care dependency (HR 1.92, CI 1.44-3.43, p = 0.003). CONCLUSION: Diabetes, education level, and care dependency are associated with TVA at dialysis initiation in patients with CKD.

GLUT10 maintains the integrity of major arteries through regulation of redox homeostasis and mitochondrial function.

Glucose transporter 10 (GLUT10) is a member of the GLUT family of membrane transporters, and mutations in this gene cause arterial tortuosity syndrome (ATS). However, the physiological role and regulation of GLUT10 in arteries remains unclear. To further understand its physiological roles in major arteries, we examined the regulatory mechanisms of GLUT10 in ASMCs and aortic tissues. Interestingly, we find that targeting of GLUT10 to mitochondria is increased in ASMCs under both stress and aging conditions, which enhances dehydroascorbic acid (DHA) uptake and maintains intracellular ascorbic acid (AA) levels. We further demonstrate that the targeting of GLUT10 to mitochondria is important to maintain redox homeostasis, mitochondrial structure and mitochondrial function in ASMCs. A missense mutation of GLUT10 (Glut10G128E) impairs mitochondrial targeting in ASMCs. Consequently, ASMCs isolated from Glut10G128E mice exhibit increased reactive oxygen species (ROS) levels, fragmented mitochondria and impaired mitochondrial function, as well as enhanced cell proliferation and migration. In vivo, mitochondrial structure is altered, and ROS levels are heightened in aortic tissues of Glut10G128E mice. Furthermore, increased number and disorganization of ASMCs, along with progressive arterial wall remodeling were observed in aortic tissues of Glut10G128E mice. These defects were coincident with elevated systolic blood pressure in aged Glut10G128E animals. Our results describe a novel mechanism that GLUT10 targeting to mitochondria under stress and aging condition has a critical role in maintaining AA levels, redox homeostasis and mitochondrial structure and function in ASMCs, which is likely to contribute to the maintenance of healthy vascular tissue.

Soluble α-synuclein facilitates priming and fusion by releasing Ca2+ from the thapsigargin-sensitive Ca2+ pool in PC12 cells.

α-Synuclein is associated with Parkinson's disease, and is mainly localized in presynaptic terminals and regulates exocytosis, but its physiological roles remain controversial. Here, we studied the effects of soluble and aggregated α-synuclein on exocytosis, and explored the molecular mechanism by which α-synuclein interacts with regulatory proteins, including Rab3A, Munc13-1 (also known as Unc13a) and Munc18-1 (also known as STXBP1), in order to regulate exocytosis. Through fluorescence recovery after photobleaching experiments, overexpressed α-synuclein in PC12 cells was found to be in a monomeric form, which promotes exocytosis. In contrast, aggregated α-synuclein induced by lactacystin treatment inhibits exocytosis. Our results show that α-synuclein is involved in vesicle priming and fusion. α-Synuclein and phorbol 12-myristate 13-acetate (PMA), which is known to enhance vesicle priming mediated by Rab3A, Munc13-1 and Munc18-1, act on the same population of vesicles, but regulate priming independently. Furthermore, the results show a novel effects of α-synuclein on mobilizing Ca2+ release from thapsigargin-sensitive Ca2+ pools to enhance the ATP-induced [Ca2+]i increase, which enhances vesicle fusion. Our results provide a detailed understanding of the action of α-synuclein during the final steps of exocytosis.

3D Imaging of Tapetal Mitochondria Suggests the Importance of Mitochondrial Fission in Pollen Growth.

Mitochondrial fission occurs frequently in plant cells, but its biological significance is poorly understood because mutants specifically impaired in mitochondrial fission do not show obvious defects in vegetative growth. Here, we revealed that the production of viable pollen was reduced in mutants lacking one of the three main proteins involved in mitochondrial fission in Arabidopsis (Arabidopsis thaliana), DYNAMIN-RELATED PROTEIN3A (DRP3A)/Arabidopsis DYNAMIN-LIKE PROTEIN2A, DRP3B, and ELONGATED MITOCHONDRIA1 (ELM1). In drp3b and elm1, young microspores contained an abnormal number of nuclei, and mature pollen had aberrant accumulation of lipids in their coat and an irregular pollen outer wall. Because the formation of the pollen wall and coat is mainly associated with tapetal function, we used 3D imaging to quantify geometric and textural features of cells and mitochondria in the tapetum at different stages, using isolated single tapetal cells in which the in vivo morphology and volume of cells and mitochondria were preserved. Tapetal cells and their mitochondria changed in the volume and morphology at different developmental stages. Defective mitochondrial fission in the elm1 and drp3b mutants caused changes in mitochondrial status, including mitochondrial elongation, abnormal mitochondrial ultrastructure, a decrease in cross-sectional area, and a slight alteration of mitochondrial distribution, as well as a large reduction in mitochondrial density. Our studies suggest that mitochondrial fission is required for proper mitochondrial status in the tapetum and possibly in pollen as well and therefore plays an important role for the production of viable pollen.

Hypothyroidism is associated with all-cause mortality in a national cohort of chronic haemodialysis patients.

AIM: The prevalence of hypothyroidism is high in haemodialysis (HD) patients and hypothyroidism increases all-cause mortality in HD patients. Comorbidities are common in HD patients and are associated with both mortality and hypothyroidism. The aim of the study is to explore the effect of the interactions of comorbidities and hypothyroidism on all-cause mortality in HD patients. METHOD: Patients with hypothyroidism (ICD-9-CM 244.0, 244.1, and 244.9) and matched patients without hypothyroidism in the Registry for Catastrophic Illness Patient Database of Taiwan Health Insurance from 2000 to 2010 were analyzed. The association of hypothyroidism and risk of all-cause mortality was analyzed using Cox proportional hazard regression. RESULT: Nine hundred and eight HD patients with hypothyroidism and 3632 sex-, age-, gender- matched HD patients without hypothyroidism were analyzed. Hypothyroidism was associated with increased all-cause mortality with an adjusted hazard ratio of 1.22 [95% confidence interval (CI): 1.10-1.36, P < 0.001]. TRT may decrease mortality associated with hypothyroidism (P < 0.001). There was a significant interaction (P = 0.04) between diabetes and hypothyroidism. There was no significant interaction found in hypothyroidism and the following comorbidities: hyperlipidaemia, hypertension, chronic obstructive pulmonary disease, coronary artery disease, stroke, peripheral arterial disease, asthma, congestive heart failure and cancer. CONCLUSION: Hypothyroidism is associated with increased all-cause mortality in chronic HD patients. The interaction of hypothyroidism and diabetes, but not other common comorbidities in HD patients, has an effect on mortality risks.

Comparison of the risk of non-traumatic lower extremity amputation between haemodialysis and peritoneal dialysis patients with end-stage renal disease.

AIM: We used insurance claims data of Taiwan to compare the risk of non-traumatic lower extremity amputation between haemodialysis (HD) and peritoneal dialysis (PD) patients. METHODS: We identified 77 669 HD patients and 10 035 PD patients without prior amputation from 2000 to 2010. Incidence rates and hazard ratios (HRs) of lower extremity amputation, and subsequent 30-day mortality after amputation were evaluated up to 31 December 2011. RESULTS: There were 2427 and 216 patients undergoing lower extremity amputation during follow-up in the HD and PD groups with incidence rates of 8.35 and 5.79 per 1000 person-years, respectively. Compared with the HD group, the overall adjusted HR of lower extremity amputation for the PD group was 1.27 (95% CI = 1.10-1.46). The impact of diabetes status on the risk of lower extremity amputation interacted with dialysis modality significantly (P < 0.001). Compared with the corresponding HD patients, the PD patients with diabetes had an adjusted HR of 1.44 (95% CI = 1.24-1.67) for amputation, whereas those without diabetes had an adjusted HR of 0.58 (95% CI = 0.36-0.95). The subsequent 30-day mortality rates after amputation were not significantly different between the HD and PD groups (8.45% vs. 9.72%) with an adjusted odds ratio of 1.41 (95% CI = 0.87-2.28, PD versus HD). CONCLUSION: Compared with corresponding HD patients, the amputation risk is higher for PD patients with diabetes, while the risk is lower for PD patients without diabetes. Dialysis patients have a high 30-day mortality risk after amputation.

Development of a Wearable Instrumented Vest for Posture Monitoring and System Usability Verification Based on the Technology Acceptance Model.

Body posture and activity are important indices for assessing health and quality of life, especially for elderly people. Therefore, an easily wearable device or instrumented garment would be valuable for monitoring elderly people's postures and activities to facilitate healthy aging. In particular, such devices should be accepted by elderly people so that they are willing to wear it all the time. This paper presents the design and development of a novel, textile-based, intelligent wearable vest for real-time posture monitoring and emergency warnings. The vest provides a highly portable and low-cost solution that can be used both indoors and outdoors in order to provide long-term care at home, including health promotion, healthy aging assessments, and health abnormality alerts. The usability of the system was verified using a technology acceptance model-based study of 50 elderly people. The results indicated that although elderly people are anxious about some newly developed wearable technologies, they look forward to wearing this instrumented posture-monitoring vest in the future.

Development of Home-Based Frailty Detection Device Using Wireless Sensor Networks.

This study develops a home-based frailty detection device that uses embedded systems and wireless sensing technology. This system helps monitor the impact of aging among the elderly through wireless automatic detection. The detection system consists of four devices. The first device, called eScale, simulates the traditional falling ruler test to measure reaction time. Another device, called eChair, measures the pressure exerted by a test subject through a pressure sensor. It is used to test three symptoms of frailty, namely slowness of movement, physical weakness, and body weight. The third device, called ePad, consists of a soft membrane switch placed on the ground to detect footsteps and is used to test balance. The fourth device, called eReach, measures displacement through ultrasound sensors. It is used to carry out the functional reach test. The sampling rate of each device is the main factor that determines system performance. When the test distance was set to 5 m for Home-Gateway, a 1-Hz sampling rate showed the best performance (98 %). Up to eight devices can be connected simultaneously to the gateway. The proposed system was compared with conventional approaches through testing with test subjects (n = 8). The results of the five tests were as follows: standing forward bend (r = 0.929), balance (r = 0.996), slowness of movement (r = 0.976), and physical weakness (r = 0.991), with p < 0.01. In the reaction time test, r = 0.871, with p < 0.1. All results suggest high correlations. Tests of aging symptoms were performed on 309 people aged over 65 years. Among males, degradation of over 20 % was found in the areas of physical weakness, slowness of movement, and functional reach. Among females, a degradation of 75 % was found in the balance test.

Classification of Benign and Malignant Breast Tumors in Ultrasound Images with Posterior Acoustic Shadowing Using Half-Contour Features.

Posterior acoustic shadowing (PAS) can bias breast tumor segmentation and classification in ultrasound images. In this paper, half-contour features are proposed to classify benign and malignant breast tumors with PAS, considering the fact that the upper half of the tumor contour is less affected by PAS. Adaptive thresholding and disk expansion are employed to detect tumor contours. Based on the detected full contour, the upper half contour is extracted. For breast tumor classification, six quantitative feature parameters are analyzed for both full contours and half contours, including standard deviation of degree (SDD), which is proposed to describe tumor irregularity. Fifty clinical cases (40 with PAS and 10 without PAS) were used. Tumor circularity (TC) and SDD were both effective full- and half-contour parameters in classifying images without PAS. Half-contour TC [74 % accuracy, 72 % sensitivity, 76 % specificity, 0.78 area under the receiver operating characteristic curve (AUC), p > 0.05] significantly improved the classification of breast tumors with PAS compared to that with full-contour TC (54 % accuracy, 56 % sensitivity, 52 % specificity, 0.52 AUC, p > 0.05). Half-contour SDD (72 % accuracy, 76 % sensitivity, 68 % specificity, 0.81 AUC, p < 0.05) improved the classification of breast tumors with PAS compared to that with full-contour SDD (62 % accuracy, 80 % sensitivity, 44 % specificity, 0.61 AUC, p > 0.05). The proposed half-contour TC and SDD may be useful in classifying benign and malignant breast tumors in ultrasound images affected by PAS.

Semi-automatic breast ultrasound image segmentation based on mean shift and graph cuts.

Computerized tumor segmentation on breast ultrasound (BUS) images remains a challenging task. In this paper, we proposed a new method for semi-automatic tumor segmentation on BUS images using Gaussian filtering, histogram equalization, mean shift, and graph cuts. The only interaction required was to select two diagonal points to determine a region of interest (ROI) on an input image. The ROI image was shrunken by a factor of 2 using bicubic interpolation to reduce computation time. The shrunken image was smoothed by a Gaussian filter and then contrast-enhanced by histogram equalization. Next, the enhanced image was filtered by pyramid mean shift to improve homogeneity. The object and background seeds for graph cuts were automatically generated on the filtered image. Using these seeds, the filtered image was then segmented by graph cuts into a binary image containing the object and background. Finally, the binary image was expanded by a factor of 2 using bicubic interpolation, and the expanded image was processed by morphological opening and closing to refine the tumor contour. The method was implemented with OpenCV 2.4.3 and Visual Studio 2010 and tested for 38 BUS images with benign tumors and 31 BUS images with malignant tumors from different ultrasound scanners. Experimental results showed that our method had a true positive rate (TP) of 91.7%, a false positive (FP) rate of 11.9%, and a similarity (SI) rate of 85.6%. The mean run time on Intel Core 2.66 GHz CPU and 4 GB RAM was 0.49 ± 0.36 s. The experimental results indicate that the proposed method may be useful in BUS image segmentation.

Cognitive inference device for activity supervision in the elderly.

Human activity, life span, and quality of life are enhanced by innovations in science and technology. Aging individual needs to take advantage of these developments to lead a self-regulated life. However, maintaining a self-regulated life at old age involves a high degree of risk, and the elderly often fail at this goal. Thus, the objective of our study is to investigate the feasibility of implementing a cognitive inference device (CI-device) for effective activity supervision in the elderly. To frame the CI-device, we propose a device design framework along with an inference algorithm and implement the designs through an artificial neural model with different configurations, mapping the CI-device's functions to minimise the device's prediction error. An analysis and discussion are then provided to validate the feasibility of CI-device implementation for activity supervision in the elderly.

Involvement of Rab3A in vesicle priming during exocytosis: interaction with Munc13-1 and Munc18-1.

Rab3A is a small G-protein of the Rab family that is involved in the late steps of exocytosis. Here, we studied the role of Rab3A and its relationship with Munc13-1 and Munc18-1 during vesicle priming. Phorbol 12-myristate 13-acetate (PMA) is known to enhance the percentage of fusion-competent vesicles and this is mediated by protein kinase C (PKC)-independent Munc13-1 activation and PKC-dependent dissociation of Munc18-1 from syntaxin 1a. Our results show that the effects of PMA varied in cells overexpressing Rab3A or mutants of Rab3A and in cells with Rab3A knockdown. When Munc13-1 was overexpressed in Rab3A knockdown cells, secretion was completely inhibited. In cells overexpressing a Rab-interacting molecule (RIM)-binding deficient Munc13-1 mutant, 128-Munc13-1, the effects of Rab3A on PMA-induced secretion was abolished. The effect of PMA, which disappeared in cells overexpressing GTP-Rab3A (Q81L), could be reversed by co-expressing Munc18-1 but not its mutant R39C, which is unable to bind to syntaxin 1a. In cells overexpressing Munc18-1, manipulation of Rab3A activity had no effect on secretion. Finally, Munc18-1 enhanced the dissociation of Rab3A, and such enhancement correlated with exocytosis. In summary, our results support the hypothesis that the Rab3A cycle is coupled with the activation of Munc13-1 via RIM, which accounts for the regulation of secretion by Rab3A. Munc18-1 acts downstream of Munc13-1/RIM/Rab3A and interacts with syntaxin 1a allowing vesicle priming. Furthermore, Munc18-1 promotes Rab3A dissociation from vesicles, which then results in fusion.