195 research outputs found

    A phase-locked frequency divide-by-3 optical parametric oscillator

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    Accurate phase-locked 3:1 division of an optical frequency was achieved, by using a continuous-wave (cw) doubly resonant optical parametric oscillator. A fractional frequency stability of 2*10^(-17) of the division process has been achieved for 100s integration time. The technique developed in this work can be generalized to the accurate phase and frequency control of any cw optical parametric oscillator.Comment: 4 pages, 5 figures in a postscript file. To appear in a special issue of IEEE Trans. Instr. & Meas., paper FRIA-2 presented at CPEM'2000 conference, Sydney, May 200

    Income-related health transfers principles and orderings of joint distributions of income and health

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    The objective of this article is to provide the analyst with the necessary tools that allow for a robust ordering of joint distributions of health and income. We contribute to the literature on the measurement and inference of socioeconomic health inequality in three distinct but complementary ways. First, we provide a formalization of the socioeconomic health inequality-specific ethical principle introduced by Erreygers et al. (2012). Second, we propose new graphical tools and dominance tests for the identification of robust orderings of joint distributions of income and health associated with this new ethical principle. Finally, based on both pro-poor and pro-extreme ranks ethical principles we address a very important aspect of dominance literature: the inference. To illustrate the empirical relevance of the proposed approach, we compare joint distributions of income and a health-related behavior in the United States in 1997 and 2014

    Two-stage laparoscopic liver resection for bilateral colorectal liver metastasis

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    Abstract Background Hepatectomy may prolong the survival of colorectal cancer patients with liver metastases. Two-stage liver surgery is a valid option for the treatment of bilobar colorectal liver metastasis. This video demonstrates technical aspects of a two-stage pure laparoscopic hepatectomy for bilateral liver metastasis. To the authors' knowledge, this is the first description of a two-stage laparoscopic liver resection in the English literature. Methods A 54-year-old man with right colon cancer and synchronous bilobar colorectal liver metastasis underwent laparoscopic right colon resection followed by oxaliplatinbased chemotherapy. The patient then was referred for surgical treatment of liver metastasis. Liver volumetry showed a small left liver remnant. Surgical planning was for a totally laparoscopic two-stage liver resection. The first stage involved laparoscopic resection of segment 3 and ligature of the right portal vein. The postoperative pathology showed high-grade liver steatosis. After 4 weeks, the left liver had regenerated, and volumetry of left liver was 43%. The second stage involved laparoscopic right hepatectomy using the intrahepatic Glissonian approach. Intrahepatic access to the main right Glissonian pedicle was achieved with two small incisions, and an endoscopic vascular stapling device was inserted between these incisions and fired. The line of liver transection was marked following the ischemic area. Liver transection was accomplished with the Harmonic scalpel and an endoscopic stapling device. The specimen was extracted through a suprapubic incision. The falciform ligament was fixed to maintain the left liver in its original anatomic position, avoiding hepatic vein kinking and outflow syndrome. Results The operative time was 90 min for stage 1 and 240 min for stage 2 of the procedure. The recoveries after the first and second operations were uneventful, and the patient was discharged on postoperative days 2 and 7, respectively. Conclusion Two-stage liver resections can be performed safely using laparoscopy. The intrahepatic Glissonian approach is a useful tool for pedicle control of the right liver, especially after previous dissection of the hilar plate

    Severe symptomatic hypocalcemia from HIV related hypoparathyroidism

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    We report the case of a 54-year-old Caucasian female who presented with a two-year history of persistent hypocalcemia requiring multiple hospitalizations. Her medical history was significant for HIV diagnosed four years ago. She denied any history of prior neck surgery or radiation. Her vital signs were stable with an unremarkable physical exam. Pertinent medications included calcium carbonate, vitamin D3, calcitriol, efavirenz, emtricitabine, tenofovir disoproxil, hydrochlorothiazide, and inhaled budesonide/formoterol. Laboratory testing showed total calcium of 5.7 mg/dL (normal range: 8.4-10.2 mg/dL), ionized calcium of 2.7 mg/dL (normal range: 4.5-5.5 mg/dL), serum phosphate of 6.3 mg/dL (normal range: 2.7-4.5 mg/dL), and intact PTH of 7.6 pg/mL (normal range: 15-65 pg/mL). She was diagnosed with primary hypoparathyroidism. Anti-calcium-sensing receptor antibodies and NALP5 antibodies were tested and found to be negative. During subsequent clinic visits, doses of calcium supplements and calcitriol were titrated. Last corrected serum calcium level was 9.18 mg/dL. She was subsequently lost to follow-up. This case gives insight into severe symptomatic hypocalcemia from primary hypoparathyroidism attributed to HIV infection. We suggest that calcium levels should be closely monitored in patients with HIV infection

    Robotic Resection of Intraductal Neoplasm of the Pancreas

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    Abstract Background: Minimally invasive techniques have been revolutionary and provide clinical evidence of decreased morbidity and comparable efficacy to traditional open surgery. Computer-assisted surgical devices have recently been approved for general surgical use. Aim: The aim of this study was to report the first known case of pancreatic resection with the use of a computerassisted, or robotic, surgical device in Latin America. Patient and Methods: A 37-year-old female with a previous history of radical mastectomy for bilateral breast cancer due to a BRCA2 mutation presented with an acute pancreatitis episode. Radiologic investigation disclosed an intraductal pancreatic neoplasm located in the neck of the pancreas with atrophy of the body and tail. The main pancreatic duct was enlarged. The surgical decision was to perform a laparoscopic subtotal pancreatectomy, using the da Vinci Ã’ robotic system (Intuitive Surgical, Sunnyvale, CA). Five trocars were used. Pancreatic transection was achieved with vascular endoscopic stapler. The surgical specimen was removed without an additional incision. Results: Operative time was 240 minutes. Blood loss was minimal, and the patient did not receive a transfusion. The recovery was uneventful, and the patient was discharged on postoperative day 4. Conclusions: The subtotal laparoscopic pancreatic resection can safely be performed. The da Vinci robotic system allowed for technical refinements of laparoscopic pancreatic resection. Robotic assistance improved the dissection and control of major blood vessels due to three-dimensional visualization of the operative field and instruments with wrist-type end-effectors

    ALPPS Procedure with the Use of Pneumoperitoneum

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    ABSTRACT Background. A new method for liver hypertrophy was recently introduced, the so-called associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) procedure. We present a video of an ALPPS procedure with the use of pneumoperitoneum. Methods. A 29-year-old woman with colon cancer and synchronous liver metastasis underwent a two-stage liver resection by the ALPPS technique because of an extremely small future liver remnant. Results. The first operation began with 30 min pneumoperitoneum. Anatomical resection of segment 2 was performed, followed by multiple enucleations on the left liver. The right portal vein was ligated and the liver partitioned. The abdominal cavity was partially closed, and a 10 mm trocar was left to create a pneumoperitoneum for additional 30 min. The patient had an adequate future liver remnant volume after 7 days, but she was not clinically fit for the second stage of therapy, so it was postponed. She was discharged on day 7 after surgery. The second stage took place 3 weeks later and consisted of an en-bloc right trisectionectomy extended to segment 1. The patient recovered and was discharged 9 days after second-stage surgery. Postoperative CT scan revealed an enlarged remnant liver. Conclusions. The ALPPS procedure is a new revolutionary technique that permits R0 resection even in patients with massive liver metastasis. The use of pneumoperitoneum during the first stage is an easy tool that may prevent hard adhesions, allowing an easier second stage. This video may help oncological surgeons to perform and standardize this challenging procedure. Surgical resection is the only curative modality of treatment in patients with colorectal liver metastases. Although multiple and bilobar metastases are correlated with the worst prognosis, this condition should not be considered a contraindication to hepatic resection, because even in this situation, surgery is still the only curative treatment. 1-3 The most common strategy for these patients is to perform neoadjuvant therapy followed by two-stage hepatectomy with minor resections on the left lateral liver (future liver remnant, FLR) combined with right portal vein occlusion as the first stage, followed by right trisectionectomy. 2 However, insufficient FLR volume may preclude liver resection even after portal vein occlusion. To overcome this problem, a new method to increase liver hypertrophy before extended hepatectomy was recently described by a German multicenter study and validated by the group of de Santibañes and Clavien

    Role of biomarkers and emerging technologies in defining and assessing neurobiological recovery after sport-related concussion: a systematic review

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    OBJECTIVE: Determine the role of fluid-based biomarkers, advanced neuroimaging, genetic testing and emerging technologies in defining and assessing neurobiological recovery after sport-related concussion (SRC). DESIGN: Systematic review. DATA SOURCES: Searches of seven databases from 1 January 2001 through 24 March 2022 using keywords and index terms relevant to concussion, sports and neurobiological recovery. Separate reviews were conducted for studies involving neuroimaging, fluid biomarkers, genetic testing and emerging technologies. A standardised method and data extraction tool was used to document the study design, population, methodology and results. Reviewers also rated the risk of bias and quality of each study. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Studies were included if they: (1) were published in English; (2) represented original research; (3) involved human research; (4) pertained only to SRC; (5) included data involving neuroimaging (including electrophysiological testing), fluid biomarkers or genetic testing or other advanced technologies used to assess neurobiological recovery after SRC; (6) had a minimum of one data collection point within 6 months post-SRC; and (7) contained a minimum sample size of 10 participants. RESULTS: A total of 205 studies met inclusion criteria, including 81 neuroimaging, 50 fluid biomarkers, 5 genetic testing, 73 advanced technologies studies (4 studies overlapped two separate domains). Numerous studies have demonstrated the ability of neuroimaging and fluid-based biomarkers to detect the acute effects of concussion and to track neurobiological recovery after injury. Recent studies have also reported on the diagnostic and prognostic performance of emerging technologies in the assessment of SRC. In sum, the available evidence reinforces the theory that physiological recovery may persist beyond clinical recovery after SRC. The potential role of genetic testing remains unclear based on limited research. CONCLUSIONS: Advanced neuroimaging, fluid-based biomarkers, genetic testing and emerging technologies are valuable research tools for the study of SRC, but there is not sufficient evidence to recommend their use in clinical practice. PROSPERO REGISTRATION NUMBER: CRD42020164558

    The Concussion Recognition Tool 5th Edition (CRT5): Background and rationale

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    The Concussion Recognition Tool 5 (CRT5) is the most recent revision of the Pocket Sport Concussion Assessment Tool 2 that was initially introduced by the Concussion in Sport Group in 2005. The CRT5 is designed to assist non-medically trained individuals to recognise the signs and symptoms of possible sport-related concussion and provides guidance for removing an athlete from play/sport and to seek medical attention. This paper presents the development of the CRT5 and highlights the differences between the CRT5 and prior versions of the instrument

    Rank-based poverty measures and poverty ordering with an application to Tunisia

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    Using the normative approach, we develop a class of poverty measures that is function of a weighting system. Each particular weighting function corresponds to a particular social judgment. This offers the decision-maker a large selection of social preferences functions, and he can choose the one that best represents his social judgment. We also develop new concepts of a-extended TIP curves. They are used to establish the conditions of the robust and unanimous poverty ranking of our measures. These conditions are in terms of second-and higher-degree TIP dominance. Finally, we provide an empirical illustration using Tunisian data on the 2005–2010 period.info:eu-repo/semantics/publishedVersio
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