Synchronization of active mechanical oscillators by an inertial load

Motivated by the operation of myogenic (self-oscillatory) insect flight muscle, we study a model consisting of a large number of identical oscillatory contractile elements joined in a chain, whose end is attached to a damped mass-spring oscillator. When the inertial load is small, the serial coupling favors an antisynchronous state in which the extension of one oscillator is compensated by the contraction of another, in order to preserve the total length. However, a sufficiently massive load can sychronize the oscillators and can even induce oscillation in situations where isolated elements would be stable. The system has a complex phase diagram displaying quiescent, synchronous and antisynchrononous phases, as well as an unsual asynchronous phase in which the total length of the chain oscillates at a different frequency from the individual active elements.Comment: 5 pages, 4 figures, To appear in Phys. Rev. Let

Cervical Implant Allergy With Chronic Neck Pain: A Case Report

A 57-year-old woman underwent cervical implant surgery for a dislocated cervical spine fracture, and she complained of continuous intractable neck pain after surgery. Eight years later, she developed a plantar skin rash, subsequently diagnosed as a metal allergy, and metal dentures were replaced with ceramic ones. The skin rash, however, persisted for four more years after that and was eventually treated with cervical implant removal. Subsequently, her skin rash and her neck pain improved simultaneously. This synchronous improvement strongly suggested that the neck pain could have been caused by a cervical implant allergy. We discuss a case of posterior cervical implant allergy that presented with neck pain and plantar skin rash years after surgery

Traction Radiculopathy After Surgery for Lumbar Spinal Metastasis: A Case Report

Treatment of spinal metastasis has attracted much attention globally, especially in Japan, with the advancement of cancer therapy. Among the metastases, those from breast and prostate cancers may be more important than others considering the high incidence of bone metastasis and the long-term prognosis. This condition often results in surgical procedures of spinal metastases to improve cancer patients' quality of life (QOL). In the present case, a patient with lumbar metastasis of breast cancer presented with right L5 nerve palsy after palliative laminectomy surgery with posterior fusion. The nerve palsy had improved after additional bone resection around the right L5 root. The mechanism of this postoperative leg paralysis was subclinical nerve root damage due to the narrowing of the intervertebral foramen caused by the tumor protrusion like lumber disc hernia and the stretching of the nerve roots caused by the posterior shift of the dural tube. When performing decompression and fixation of a metastatic spine showing a herniated tumor formed by a tumor protruding posteriorly into the intervertebral foraminal space, sufficient tumor mass debulking should be considered to avoid postoperative intervertebral foraminal stenosis

Matrix theory origins of non-geometric fluxes

We explore the origins of non-geometric fluxes within the context of M theory described as a matrix model. Building upon compactifications of Matrix theory on non-commutative tori and twisted tori, we formulate the conditions which describe compactifications with non-geometric fluxes. These turn out to be related to certain deformations of tori with non-commutative and non-associative structures on their phase space. Quantization of flux appears as a natural consequence of the framework and leads to the resolution of non-associativity at the level of the unitary operators. The quantum-mechanical nature of the model bestows an important role on the phase space. In particular, the geometric and non-geometric fluxes exchange their properties when going from position space to momentum space thus providing a duality among the two. Moreover, the operations which connect solutions with different fluxes are described and their relation to T-duality is discussed. Finally, we provide some insights on the effective gauge theories obtained from these matrix compactifications.Comment: 1+31 pages, reference list update

Clearance of technetium-99m-DTPA and HRCT findings in the evaluation of patients with Idiopathic Pulmonary Fibrosis

BACKGROUND: Clearance of inhaled technetium-labeled diethylenetriamine pentaacetate ((99m)Tc-DTPA) is a marker of epithelial damage and an index of lung epithelial permeability. The aim of this study was to investigate the role of (99m)Tc-DTPA scan in patients with Idiopathic Pulmonary Fibrosis (IPF). Our hypothesis is that the rate of pulmonary (99m)Tc-DTPA clearance could be associated with extent of High Resolution Computed Tomography (HRCT) abnormalities, cell differential of bronchoalveolar lavage fluid (BALF) and pulmonary function tests (PFTs) in patients with IPF. METHODS: We studied prospectively 18 patients (14 male, 4 female) of median age 67yr (range 55–81) with histologically proven IPF. HRCT scoring included the mean values of extent of disease. Mean values of these percentages represented the Total Interstitial Disease Score (TID). DTPA clearance was analyzed according to a dynamic study using a Venticis II radioaerosol delivery system. RESULTS: The mean (SD) TID score was 36 ± 12%, 3 patients had mild, 11 moderate and 4 severe TID. Abnormal DTPA clearance half-time (t(1/2)<40 min) was found in 17/18 (94.5%) [mean (SD) 29.1 ± 8.6 min]. TID was weakly correlated with the DTPA clearance (r = -0.47, p = 0.048) and with % eosinophils (r = 0.475, p = 0.05). No correlation was found between TID score or DTPA and PFTs in IPF patients. CONCLUSION: Our data suggest that (99m)Tc-DTPA lung scan is not well associated with HRCT abnormalities, PFTs, and BALF cellularity in patients with IPF. Further studies in large scale of patients are needed to define the role of this technique in pulmonary fibrosis

Development of miracle medicines from sialic acids

Sialic acids are electronegatively charged C9-sugars and are considered to play important roles in higher animals and some microorganisms. Denoting their significance, understanding and exploiting the complexity of the sialic acids has been referred to as the “the third language of life”. In essence, “sialic acid derivatives possess a harmonious shape and good balance between two opposing hydrophilic and hydrophobic parts, meaning that they should display various kinds of potentially unique and possibly conflicting physiological activities (glycolipoids)”. Consequently, there are good omens that unprecedented ‘miracle’ medicines could be developed from sialic acid derivatives. In this review, the first problem, the preparation of sialic acids, is covered, the synthesis of sialic acid derivatives and confirmation of their structures obviously being of critical significance. In addition we needed to confirm their precise stereochemistry and a hydrolysis method has been developed for confirmation of the anomeric position. Several of the compounds have already demonstrated interesting bioactivity

Postnatal Pancreatic Islet β Cell Function and Insulin Sensitivity at Different Stages of Lifetime in Rats Born with Intrauterine Growth Retardation

Epidemiological studies have linked intrauterine growth retardation (IUGR) to the metabolic diseases, consisting of insulin resistance, type 2 diabetes, obesity and coronary artery disease, during adult life. To determine the internal relationship between IUGR and islet β cell function and insulin sensitivity, we established the IUGR model by maternal nutrition restriction during mid- to late-gestation. Glucose tolerance test and insulin tolerance test(ITT) in vivo and glucose stimulated insulin secretion(GSIS) test in vitro were performed at different stages in IUGR and normal groups. Body weight, pancreas weight and pancreas/body weight of IUGR rats were much lower than those in normal group before 3 weeks of age. While the growth of IUGR rats accelerated after 3 weeks, pancreas weight and pancreas/body weight remained lower till 15 weeks of age. In the newborns, the fasting glucose and insulin levels of IUGR rats were both lower than those of controls, whereas glucose levels at 120 and 180 min after glucose load were significantly higher in IUGR group. Between 3 and 15 weeks of age, both the fasting glucose and insulin levels were elevated and the glucose tolerance was impaired with time in IUGR rats. At age 15 weeks, the area under curve of insulin(AUCi) after glucose load in IUGR rats elevated markedly. Meanwhile, the stimulating index of islets in IUGR group during GSIS test at age 15 weeks was significantly lower than that of controls. ITT showed no significant difference in two groups before 7 weeks of age. However, in 15-week-old IUGR rats, there was a markedly blunted glycemic response to insulin load compared with normal group. These findings demonstrate that IUGR rats had both impaired pancreatic development and deteriorated glucose tolerance and insulin sensitivity, which would be the internal causes why they were prone to develop type 2 diabetes