Biomimetic learning of hand gestures in a humanoid robot.

Hand gestures are a natural and intuitive form of communication, and integrating this communication method into robotic systems presents significant potential to improve human-robot collaboration. Recent advances in motor neuroscience have focused on replicating human hand movements from synergies also known as movement primitives. Synergies, fundamental building blocks of movement, serve as a potential strategy adapted by the central nervous system to generate and control movements. Identifying how synergies contribute to movement can help in dexterous control of robotics, exoskeletons, prosthetics and extend its applications to rehabilitation. In this paper, 33 static hand gestures were recorded through a single RGB camera and identified in real-time through the MediaPipe framework as participants made various postures with their dominant hand. Assuming an open palm as initial posture, uniform joint angular velocities were obtained from all these gestures. By applying a dimensionality reduction method, kinematic synergies were obtained from these joint angular velocities. Kinematic synergies that explain 98% of variance of movements were utilized to reconstruct new hand gestures using convex optimization. Reconstructed hand gestures and selected kinematic synergies were translated onto a humanoid robot, Mitra, in real-time, as the participants demonstrated various hand gestures. The results showed that by using only few kinematic synergies it is possible to generate various hand gestures, with 95.7% accuracy. Furthermore, utilizing low-dimensional synergies in control of high dimensional end effectors holds promise to enable near-natural human-robot collaboration.

An insight into optical beam induced current microscopy: Concepts and applications.

Laser scanning optical beam induced current (OBIC) microscopy has become a powerful and nondestructive alternative to other complicated methods like electron beam induced current (EBIC) microscopy, for high resolution defect analysis of electronic devices. OBIC is based on the generation of electron-hole pairs in the sample due to the raster scanning of a focused laser beam with energy equal or greater than the band gap energy and synchronized detection of resultant current profile with respect to the beam positions. OBIC is particularly suitable to localize defect sites caused by metal-semiconductor interdiffusion or electrostatic discharge (ESD). OBIC signals, thus, are capable of revealing the parameters/factors directly related to the reliability and efficiency of the electronic device under test (DUT). In this review, the basic principles of OBIC microscopy strategies and their notable applications in semiconductor device characterization are elucidated. An overview on the developments of OBIC microscopy is also presented. Specifically, the recent progresses on the following three OBIC measurement strategies have been reviewed, which include continuous laser based single photon OBIC, pulsed laser based single photon OBIC, and multiphoton OBIC microscopy for three-dimensional mapping of photocurrent response of electronic devices at high spatiotemporal resolution. Challenges and future prospects of OBIC in characterizing complex electronic devices are also discussed. HIGHLIGHTS: Characterization of electronic device quality is of paramount importance. Optical beam induced current (OBIC) microscopy offers spatially resolved mapping of local electronic properties. This review presents the principle and notable applications of OBIC microscopy.

Opioid Use After Nephrectomy for Kidney Cancer in Ontario: A Population-Based Study.

OBJECTIVE: To compare the odds of early and prolonged post-operative opioid use in patients undergoing minimally invasive surgery (MIS) vs open surgery for nephrectomy. METHODS: For opioid-naïve patients in Ontario who underwent nephrectomy for kidney cancer (1994-2017, n = 7900), post-discharge opioid use was determined by prescriptions in the Ontario Drug Benefit database (age ≥65 years) and the Narcotics Monitoring System (all patients from 2012). Early opioid use was defined as ≥1 prescription 1-90 days after surgery. Two separate definitions of prolonged opioid use were examined: (1) prescription(s) for ≥60 days during post-operative days 90-365; (2) ≥1 prescriptions between both of: 1-90 days AND 91-180 days after surgery. Predictors of opioid use were assessed using multivariable generalized estimating equation logistic regression, accounting for surgeon clustering. RESULTS: Overall, 67.4% of patients received early opioid prescriptions; however, prolonged use was low, ranging from 1.6 to 4.4% of patients depending on the definition. In multivariable analysis, open nephrectomy was associated with higher odds of early opioid use compared to MIS nephrectomy (Odds Ratio [OR] 1.36, 95% Confidence Interval [CI] 1.19-1.55). Surgery type was not significantly associated with prolonged opioid use for either definition (OR 1.22, CI 0.79-1.89 and OR 1.06, CI 0.83-1.35). CONCLUSIONS: In this population-level study of patients undergoing nephrectomy for kidney cancer, patients who received open surgery were at increased odds of receiving early post-operative opioids compared to MIS. Prolonged opioid use was low overall and was not significantly with associated with type of surgery.

Strategies to Enhance ZnO Photocatalyst's Performance for Water Treatment: A Comprehensive Review.

Despite the photocatalytic organic pollutant degradation using ZnO started in 1910-1911, many challenges are still ahead, and several critical issues have to be addressed. Large band gap, and short life-time of photogenerated electrons and holes are critical issues negatively affect the photocatalytic activity of ZnO. Various approaches have been introduced to overcome these issues including intrinsic doping, extrinsic doping, and heterostructure. This review introduces unique and deep insights into tuning of the photocatalytic activity of ZnO. It starts by description of how to tune the photocatalytic activity of pristine ZnO through tuning its morphology, surface area, exposed face, and intrinsic defects. Afterward, the review explains how the Z-scheme approach succeed to address the redox weakened issue of heterojunction approach. In general, this review provides a clear image that helps the researcher to tune the photocatalytic activity of pristine ZnO and its heterostructure.

Peroxisomes: role in cellular ageing and age related disorders.

Peroxisomes are dynamic organelles essential for optimum functioning of a eukaryotic cell. Biogenesis of these organelles and the diverse functions performed by them have been extensively studied in the past decade. Their ability to perform functions depending on the cell type and growth conditions is unique and remarkable. Oxidation of fatty acids and reactive oxygen species metabolism are the two most important functions of these ubiquitous organelles. They are often referred to as both source and sink of reactive oxygen species in a cell. Recent research connects peroxisome dysfunction to fatal oxidative damage associated with ageing-related diseases/disorders. It is now widely accepted that mitochondria and peroxisomes are required to maintain oxidative balance in a cell. However, our understanding on the inter-dependence of these organelles to maintain cellular homeostasis of reactive oxygen species is still in its infancy. Herein, we summarize findings that highlight the role of peroxisomes in cellular reactive oxygen species metabolism, ageing and age-related disorders.

Clinical Characteristics and Outcomes of Late Relapse in Stage I Testicular Seminoma.

AIMS: To identify the characteristics and outcomes associated with late relapse in stage I seminoma. MATERIALS AND METHODS: A retrospective review was carried out of all patients with stage I seminoma managed at our institution between 1981 and 2011. Data were obtained from a prospectively maintained database. Late relapse was defined as tumour recurrence > 2 years after orchiectomy. RESULTS: Overall, 1060 stage I seminoma patients were managed with active surveillance (n=766) or adjuvant radiotherapy (n=294). At a median follow-up of 10.6 years (range 1.2-30), 142 patients relapsed at a median (range) of 14 (3-129) months; 128 on active surveillance and 14 after adjuvant radiotherapy. The late relapse rate for the active surveillance and adjuvant radiotherapy groups was 4% and 1%, respectively. There was no specific clinicopathological factor associated with late relapse. Isolated para-aortic node(s) was the most common relapse site in active surveillance patients either in late (88%) or early relapse (82%). Among the active surveillance group, no patients with late relapse subsequently developed a second relapse after either salvage radiotherapy (n=25) or chemotherapy (n=6), whereas in early relapse patients a second relapse was reported in seven (10%) of 72 patients treated with salvage radiotherapy and one (4%) of 23 patients who received chemotherapy; all second relapses were subsequently salvaged with chemotherapy. No patient in the adjuvant radiotherapy group developed a second relapse after salvage chemotherapy (n=10) or inguinal radiotherapy/surgery (n=4). Of seven deaths, only one was related to seminoma. Among active surveillance patients, the 10 year overall survival for late and early relapse groups were 100% and 96% (P = 0.2), whereas the 10 year cancer-specific survival rates were 100% and 99% (P = 0.3), respectively. CONCLUSIONS: In stage I seminoma, the extent and pattern of late relapse is similar to that for early relapse. For active surveillance patients, selective use of salvage radiotherapy/chemotherapy for relapse results in excellent outcomes regardless of the timing of relapse, whereas salvage radiotherapy for late relapse seems to be associated with a minimal risk of second relapse.

Safety and efficacy of photoselective vaporization of prostate in patients receiving anticoagulants.

AIM: Objective of the present study was to evaluate the safety and efficacy of photoselective vaporization of the prostate (PVP) using a 80W potassium titanyl phosphate (KTP) laser, in benign prostatic enlargement (BPE) patients who were on ongoing anticoagulant therapy during the perioperative period. METHODS: Prospectively collected laser prostatectomy patient database of our hospital for the period between July 2009-Jan 2012 was retrospectively reviewed. Data on perioperative safety, functional outcome and complications up to follow-up at 6 months of 45 eligible patients who underwent PVP-KTP and were on perioperative anticoagulant therapy (study group) was compared with 47 eligible patients who underwent PVP-KTP and were not on perioperative anticoagulant therapy (control group). P<0.05 was considered statistically significant. RESULTS: The baseline characteristics of the two groups were similar except for ASA score which was significantly higher in the study group.(2.64±0.60 vs. 1.53±0.50). Though the need (15.55% vs. 4.25% patients) and duration of postoperative irrigation (243.33±49.66 vs. 52.5±10.60 min) was significantly higher in the study group, the postoperative hemoglobin drop 24 hours postoperatively did not differ significantly between the two groups (8.54% vs. 6.48%). No patient required a blood transfusion. The overall complication rate was similar in the two groups. In both groups, significant improvement was recorded in the IPSS, QOL, Q max, PVRU and prostate volume data upto 6 months follow up with no significant differences noted. CONCLUSION: KTP-PVP can be performed safely and effectively in BPE patients on ongoing anticoagulation, without increasing the risk of perioperative bleeding or the need for blood transfusion.

A prospective randomized trial comparing three different analgesic techniques for pain control during transrectal ultrasound guided prostate biopsy: a single center experience.

AIM: The aim of this paper was to optimize pain control during transrectal ultrasound (TRUS) guided prostate biopsy, the efficacy and safety of three different analgesic techniques were compared. METHODS: Two hundred and forty patients were prospectively randomized into 3 groups before TRUS guided prostate biopsy. Group A received combined periprostatic nerve block (PPNB) and perianal-intrarectal lidocaine-prilocaine (PILP) cream; group B: PILP cream; group C: PPNB. Pain was evaluated using 10-point Visual Analog Scale (VAS). RESULTS: VAS during TRUS was lower in groups A and B vs. C (mean 1.3,1.4 vs. 5.1, P<0.001); VAS for PPNB was lower in group A and group B vs. C (mean 1.1,1.3 vs. 3.5, P<0.001). VAS for sampling wase lower in group A as compared to B and C (mean 0.6, 3.5 and 1.4, P<0.001). VAS on stratified analysis was significantly lower in groupA vs. B and C in patients <60 years, prostate >50 cc and those with lower anorectal compliance (P<0.001). The overall complication rate was similar in all three groups. CONCLUSION: The combination of PILP and PPNB provides better analgesia, especially in patients <60 years, prostate volume >50 cc and lower anorectal compliance as compared to two modalities used alone during the sampling part of TRUS guided prostate biopsy with no increase in the complication rate.

Recognition of grasp types through principal components of DWT based EMG features.

With the advancement in machine learning and signal processing techniques, electromyogram (EMG) signals have increasingly gained importance in man-machine interaction. Multifingered hand prostheses using surface EMG for control has appeared in the market. However, EMG based control is still rudimentary, being limited to a few hand postures based on higher number of EMG channels. Moreover, control is non-intuitive, in the sense that the user is required to learn to associate muscle remnants actions to unrelated posture of the prosthesis. Herein lies the promise of a low channel EMG based grasp classification architecture for development of an embedded intelligent prosthetic controller. This paper reports classification of six grasp types used during 70% of daily living activities based on two channel forearm EMG. A feature vector through principal component analysis of discrete wavelet transform coefficients based features of the EMG signal is derived. Classification is through radial basis function kernel based support vector machine following preprocessing and maximum voluntary contraction normalization of EMG signals. 10-fold cross validation is done. We have achieved an average recognition rate of 97.5%.

Demyelinating disease masquerading as a surgical problem: a case series.

INTRODUCTION: We report three cases of demyelinating disease with tumor-like presentation. This information is particularly important to both neurosurgeons and neurologists who should be aware that inflammatory demyelinating diseases can present as a mass lesion, which is indistinguishable from a tumor, both clinically and radiologically, especially when there is no evidence of temporal dissemination of this disease. CASE PRESENTATION: The first patient was a 42-year-old Malay woman who developed subacute onset of progressive quadriparesis with urinary incontinence. Magnetic resonance imaging of her spine showed an intramedullary lesion at the C5-C7 level. She was operated on and biopsy was suggestive of a demyelinating disease. Retrospective history discovered two episodes of acute onset of neurological deficits with partial recovery and magnetic resonance imaging of her brain revealed demyelinating plaques in the centrum semiovale. The second patient was a 16-year-old Malay boy who presented with symptoms of raised intracranial pressure. A computed tomography brain scan revealed obstructive hydrocephalus with a lesion adjacent to the fourth ventricle. An external ventricular drainage was inserted. Subsequently, a stereotactic biopsy was taken and histopathology was reported as demyelination. Retrospective history revealed similar episodes with full recovery in between episodes. The third case was a 28-year-old Malay man who presented with acute bilateral visual loss and confusion. Magnetic resonance imaging of his brain showed a large mass lesion in the right temporoparietal region. Biopsy was consistent with demyelinating disease. Reexamination of the patient revealed bilateral papillitis and not papilledema. Visual evoked potential was prolonged bilaterally. In all three cases, lumbar puncture for cerebrospinal fluid study was not carried out due to lack of patient consent. CONCLUSIONS: These cases illustrate the importance of considering a demyelinating disease in the differential diagnosis of a mass lesion. Critical analyses of clinical presentations coupled with good physical examination are vital in assisting clinicians to reach the correct diagnosis.

Hepatic Portal Venous Gas with Pneumatosis Intestinalis.

Hepatic portal venous gas with pneumatosis intestinalis are radiological clues of intestinal ischemia. Prompt evaluation and a high index of clinical suspicion for the diagnosis of acute mesenteric ischemia are necessary given the high mortality of this condition. We present a case of mesenteric ischemia, radiological clues to diagnosis, and associated mechanisms.

Unusual colonoscopy finding: Taenia saginata proglottid.

Infection with tapeworms is a major problem in many parts of the world. Patients may be asymptomatic or have a significant morbidity depending on the species. Infection with Taenia species is sometimes found by expulsion of eggs or proglottids in stool. Species specific diagnosis of Taenia is difficult, but possible. We present a case of Taenia saginata incidentally discovered, and risk factors for transmission, diagnosis, symptoms, and treatment.

Factors influencing mortality in acute pancreatitis: can we alter them?

Severe acture pancreatitis (SAP), a multisystem disease, is characterized by multiple organ system failure and additionally by local pancreatic complications such as necrosis, abscess, or pseudocyst. The rate of mortality in SAP, which is about 20% of all cases of acute pancreatitis (AP), may be as high as 25%, as in infected pancreatic necrosis. The factors that influence mortality in different degrees are various. Etiology for the episode, age, sex, race, ethnicity, genetic makeup, severity on admission, and the extent and nature of pancreatic necrosis (sterile vs. infected) influence the mortality. Other factors include treatment modalities such as administration of prophylactic antibiotics, the mode of feeding (TPN vs. enteral), ERCP with sphincterotomy, and surgery in selected cases. Epidemiological studies indicate that the incidence of AP is increasing along with an increase in obesity, a bad prognostic factor. Many studies have indicated a worse prognosis in idiopathic AP compared to pancreatitis induced by alcoholism or biliary stone. The risk for SAP after ERCP is the subject of extensive study. AP after trauma, organ transplant, or coronary artery bypass surgery is rare but may be serious. Since Ranson reported early prognostic criteria, a number of attempts have been made to simplify or add new clinical or laboratory studies in the early assessment of severity. Obesity, hemoconcentration on admission, presence of pleural effusion, increased fasting blood sugar, as well as creatinine, elevated CRP in serum, and urinary trypsinogen levels are some of the well-documented factors in the literature. The role of appropriate prophylactic antibiotic therapy although still is highly controversial, in properly chosen cases appears to be beneficial and well accepted in clinical practice. Early enteral nutrition has gained much support and jejunal feeding bypassing the pancreatic stimulatory effect of it in the duodenum is desirable in selected cases. The limited role for endoscopic sphincterotomy in patients with demonstrated dilated CBD with impacted stone and evidence of impending cholangitis is well documented. Surgery in AP other than for removal of the gallbladder is often limited to infected pancreatic necrosis, pseudocysts, and pancreatic abscess and in some cases of traumatic pancreatitis with a ruptured duct system. The progress in the understanding of the role of cytokines will over us opportunities to use immunomodulatory therapies to improve the outcome in SAP.