251 research outputs found
Heisenberg's uncertainty principle for simultaneous measurement of positive-operator-valued measures
A limitation on simultaneous measurement of two arbitrary positive operator
valued measures is discussed. In general, simultaneous measurement of two
noncommutative observables is only approximately possible. Following Werner's
formulation, we introduce a distance between observables to quantify an
accuracy of measurement. We derive an inequality that relates the achievable
accuracy with noncommutativity between two observables. As a byproduct a
necessary condition for two positive operator valued measures to be
simultaneously measurable is obtained.Comment: 7 pages, 1 figure. To appear in Phys. Rev.
Brain-controlled cycling system for rehabilitation following paraplegia with delay-time prediction
Objective: Robotic rehabilitation systems have been investigated to assist with motor dysfunction recovery in patients with lower-extremity paralysis caused by central nervous system lesions. These systems are intended to provide appropriate sensory feedback associated with locomotion. Appropriate feedback is thought to cause synchronous neuron firing, resulting in the recovery of function. Approach: In this study, we designed and evaluated an ergometric cycling wheelchair, with a brain-machine interface (BMI), that can force the legs to move by including normal stepping speeds and quick responses. Experiments were conducted in five healthy subjects and one patient with spinal cord injury (SCI), who experienced the complete paralysis of the lower limbs. Event-related desynchronization (ERD) in the β band (18‐28 Hz) was used to detect lower-limb motor images. Main results: An ergometer-based BMI system was able to safely and easily force patients to perform leg movements, at a rate of approximately 1.6 seconds/step (19 rpm), with an online accuracy rate of 73.1% for the SCI participant. Mean detection time from the cue to pedaling onset was 0.83±0.31 s Significance: This system can easily and safely maintain a normal walking speed during the experiment and be designed to accommodate the expected delay between the intentional onset and physical movement, to achieve rehabilitation effects for each participant. Similar BMI systems, implemented with rehabilitation systems, may be applicable to a wide range of patients
Formal Total Synthesis of Manzacidin B via Sequential Diastereodivergent Henry Reaction
A formal total synthesis of manzacidin B is described. beta,beta-Disubstituted gamma-hydroxy-beta-aminoalcohol, the key structure of manzacidin B, is stereoselectively constructed via sequential Henry reactions. By taking advantage of noncovalent interactions, such as intramolecular hydrogen bonding and chelation, we could diastereodivergently control the stereoselectivity of the Henry reaction
Risk factors for an additional port in single-incision laparoscopic cholecystectomy in patients with cholecystitis
Although single-incision laparoscopic cholecystectomy is now widely performed in patients with cholecystitis, some cases require an additional port to complete the procedure. In this study, we focused on risk factor of additional port in this surgery. We performed single-incision cholecystectomy in 75 patients with acute cholecystitis or after cholecystitis between 2010 and 2014 at Gunma University Hospital. Surgical indications followed the TG13 guidelines. Our standard procedure for single-incision cholecystectomy routinely uses two needlescopic devices. We used logistic regression analysis to identify the risk factors associated with use of an additional full-size port (5 or 10 mm). Surgical outcome was acceptable without biliary injury. Nine patients (12.0%) required an additional port, and one patient (1.3%) required conversion to open cholecystectomy because of severe adhesions around the cystic duct and common bile duct. In multivariate analysis, high C-reactive protein (CRP) values (>7.0 mg/dl) during cholecystitis attacks were significantly correlated with the need for an additional port (P = 0.009),with a sensitivity of 55.6%, specificity of 98.5%, and accuracy of 93.3%. This study indicated that the severe inflammation indicated by high CRP values during cholecystitis attacks predicts the need for an additional port
Hormonal Therapy Resistant Estrogen-receptor Positive Metastatic Breast Cancer Cohort (HORSE-BC) Study : Current Status of Treatment Selection in Japan
The Hormonal therapy resistant estrogen-receptor positive metastatic breast cancer cohort (HORSE-BC) study is a multicenter observational study evaluating the efficacy and safety of secondary endocrine therapy (ET) for postmenopausal cases of metastatic breast cancer (MBC) with poor response to primary ET. In this initial report we analyze the HORSE-BC baseline data to clarify the current status of treatment selection for MBC in Japan. Baseline data for the 50 patients enrolled in HORSE-BC were analyzed, including patient characteristics, types of secondary ET, and reasons for selecting secondary ET. Postoperative recurrence was detected in 84% of patients (42/50) and de novo stage IV breast cancer in 16% (8/50). Forty-one patients (41/50; 82%) received fulvestrant, 5 patients (10%) received selective estrogen receptor modulators (SERMs), 3 patients (6%) received ET plus a mammalian target of rapamycin (mTOR) inhibitor, and 1 patient received an aromatase inhibitor (AI) as the secondary ET. Forty-five patients selected their secondary ET based on its therapeutic effect, while 14 patients selected it based on side effects. Most patients with progression after primary ET selected fulvestrant as the secondary ET based on its therapeutic and side effects. We await the final results from the HORSE-BC study
The Naming of Names: Guidelines for Gene Nomenclature in Marchantia.
While Marchantia polymorpha has been utilized as a model system to investigate fundamental biological questions for over almost two centuries, there is renewed interest in M. polymorpha as a model genetic organism in the genomics era. Here we outline community guidelines for M. polymorpha gene and transgene nomenclature, and we anticipate that these guidelines will promote consistency and reduce both redundancy and confusion in the scientific literature
Taxanes and platinum derivatives impair Schwann cells via distinct mechanisms
Impairment of peripheral neurons by anti-cancer agents, including taxanes and platinum derivatives, has been considered to be a major cause of chemotherapy-induced peripheral neuropathy (CIPN), however, the precise underlying mechanisms are not fully understood. Here, we examined the direct effects of anti-cancer agents on Schwann cells. Exposure of primary cultured rat Schwann cells to paclitaxel (0.01 μM), cisplatin (1 μM), or oxaliplatin (3 μM) for 48 h induced cytotoxicity and reduced myelin basic protein expression at concentrations lower than those required to induce neurotoxicity in cultured rat dorsal root ganglion (DRG) neurons. Similarly, these anti-cancer drugs disrupted myelin formation in Schwann cell/DRG neuron co-cultures without affecting nerve axons. Cisplatin and oxaliplatin, but not paclitaxel, caused mitochondrial dysfunction in cultured Schwann cells. By contrast, paclitaxel led to dedifferentiation of Schwann cells into an immature state, characterized by increased expression of p75 and galectin-3. Consistent with in vitro findings, repeated injection of paclitaxel increased expression of p75 and galectin-3 in Schwann cells within the mouse sciatic nerve. These results suggest that taxanes and platinum derivatives impair Schwan cells by inducing dedifferentiation and mitochondrial dysfunction, respectively, which may be important in the development of CIPN in conjunction with their direct impairment in peripheral neurons
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