Operation of Layered LiCoO2 to Higher Voltages with a Localized Saturated Electrolyte.

The commercialization of lithium-ion batteries started with a layered LiCoO2 (LCO) cathode for portable electronics, but only 50% of its theoretical capacity can be used in practical cells due to detrimental surface and bulk degradations when charged to high voltages. We demonstrate here that the stability of the electrolyte plays a critical role in the performance of LCO at high voltages by employing a localized saturated electrolyte (LSE). With a cutoff voltage of 4.5 V, LCO achieves an initial 1 C discharge capacity of 176 mA h g-1 and a capacity retention of 80% over 230 cycles. Even with a cutoff voltage of 4.6 V, LCO with 2% aluminum doping displays an initial discharge capacity of 189 mA h g-1 at 1 C rate with 80% capacity retention over 137 cycles. With extensive analytical characterization, we show that the improved cycling stability stems from a suppression of the O3 to H1-3 phase transition as well as a robust inorganic-rich cathode-electrolyte interphase (CEI) facilitated by the LSE. This work highlights the importance of protecting the surface as well as the bulk with appropriate electrolytes for the high-voltage, higher-energy-density operation of LCO.

Half-life determination of 88Y and 89Sr.

Half-life measurements have been carried out at LNHB for 88Y using a 4pi gamma-ionisation chamber and for 89Sr using a proportional counter. The determined half-life values and associated standard uncertainties are 106.63 +/- 0.05 d for 88Y and 50.65 +/- 0.05 d for 89Sr, being consistent with relevant values reported in literature. Based on the present results and relevant literature values revised recommended half-life values and associated standard uncertainties are proposed, viz. 106.626 +/- 0.021 d for 88Y and 50.57 +/- 0.03 d for 89Sr.

Yeast Cdc42 functions at a late step in exocytosis, specifically during polarized growth of the emerging bud.

The Rho family GTPase Cdc42 is a key regulator of cell polarity and cytoskeletal organization in eukaryotic cells. In yeast, the role of Cdc42 in polarization of cell growth includes polarization of the actin cytoskeleton, which delivers secretory vesicles to growth sites at the plasma membrane. We now describe a novel temperature-sensitive mutant, cdc42-6, that reveals a role for Cdc42 in docking and fusion of secretory vesicles that is independent of its role in actin polarization. cdc42-6 mutants can polarize actin and deliver secretory vesicles to the bud, but fail to fuse those vesicles with the plasma membrane. This defect is manifested only during the early stages of bud formation when growth is most highly polarized, and appears to reflect a requirement for Cdc42 to maintain maximally active exocytic machinery at sites of high vesicle throughput. Extensive genetic interactions between cdc42-6 and mutations in exocytic components support this hypothesis, and indicate a functional overlap with Rho3, which also regulates both actin organization and exocytosis. Localization data suggest that the defect in cdc42-6 cells is not at the level of the localization of the exocytic apparatus. Rather, we suggest that Cdc42 acts as an allosteric regulator of the vesicle docking and fusion apparatus to provide maximal function at sites of polarized growth.

[Cerebrovascular chronic occlusive disease (moyamoya): case report]. / Doença cerebrovascular oclusiva crônica (moyamoya): relato de caso.

A six years old boy, Japanese descendant, born in the city of São Paulo, Brazil, arrived to the hospital with sudden loss of muscular strength at the left side of the body. The cranial computerised tomography showed a right fronto-parietal ischemia and the digital angiography by caterism of femural artery, confirmed the diagnosis of brain obstructive chronic vascular disease(moyamoya). We have checked out in the literature that previous superior aerial ways infection, frequently precede the neurological manifestations. Such symptoms are in agreement with the mentioned case. This has suggested the hypothesis of inflammatory-immunologic origin of this disease.

The Rho GTPase Rho3 has a direct role in exocytosis that is distinct from its role in actin polarity.

Budding yeast grow asymmetrically by the polarized delivery of proteins and lipids to specific sites on the plasma membrane. This requires the coordinated polarization of the actin cytoskeleton and the secretory apparatus. We identified Rho3 on the basis of its genetic interactions with several late-acting secretory genes. Mutational analysis of the Rho3 effector domain reveals three distinct functions in cell polarity: regulation of actin polarity, transport of exocytic vesicles from the mother cell to the bud, and docking and fusion of vesicles with the plasma membrane. We provide evidence that the vesicle delivery function of Rho3 is mediated by the unconventional myosin Myo2 and that the docking and fusion function is mediated by the exocyst component Exo70. These data suggest that Rho3 acts as a key regulator of cell polarity and exocytosis, coordinating several distinct events for delivery of proteins to specific sites on the cell surface.

Yeast homologues of tomosyn and lethal giant larvae function in exocytosis and are associated with the plasma membrane SNARE, Sec9.

We have identified a pair of related yeast proteins, Sro7p and Sro77p, based on their ability to bind to the plasma membrane SNARE (SNARE) protein, Sec9p. These proteins show significant similarity to the Drosophila tumor suppressor, lethal giant larvae and to the neuronal syntaxin-binding protein, tomosyn. SRO7 and SRO77 have redundant functions as loss of both gene products leads to a severe cold-sensitive growth defect that correlates with a severe defect in exocytosis. We show that similar to Sec9, Sro7/77 functions in the docking and fusion of post-Golgi vesicles with the plasma membrane. In contrast to a previous report, we see no defect in actin polarity under conditions where we see a dramatic effect on secretion. This demonstrates that the primary function of Sro7/77, and likely all members of the lethal giant larvae family, is in exocytosis rather than in regulating the actin cytoskeleton. Analysis of the association of Sro7p and Sec9p demonstrates that Sro7p directly interacts with Sec9p both in the cytosol and in the plasma membrane and can associate with Sec9p in the context of a SNAP receptor complex. Genetic analysis suggests that Sro7 and Sec9 function together in a pathway downstream of the Rho3 GTPase. Taken together, our studies suggest that members of the lethal giant larvae/tomosyn/Sro7 family play an important role in polarized exocytosis by regulating SNARE function on the plasma membrane.

Phase-contrast magnetic resonance angiography for the determination of cerebrovascular reserve.

Cerebrovascular reserve (CVR) is the potential for cerebral arteriolar dilatation to occur, in response to decreased cerebral perfusion pressure, in order to maintain constant cerebral blood flow. Diminution or absence of CVR is considered a risk factor for stroke. Current methods for determining CVR include single-photon emission computed tomography, positron emission tomography and transcranial Doppler (TCD) ultrasonography. However, significant advantages could derive from the utilization of magnetic resonance angiography (MRA) based on the concurrent acquisition of hemodynamic information (CVR and collateral flow) with phase-contrast (PC) techniques and vascular morphology with three-dimensional, time-of-flight methods. With a 1.5-T scanner and acetazolamide (AZM), an arteriolar dilator, CVR was determined in 7 normal subjects. Mean flow velocity in the middle cerebral arteries was determined by PC MRA before and after AZM administration. For comparative purposes, mean flow velocities in the same middle cerebral arteries were determined by TCD before and after AZM administration. The mean flow velocities were as follows (mean +/- standard deviation, n = 7): 40 +/- 8 (PC MRA) versus 61 +/- 10 cm/sec (TCD) before AZM treatment and 58 +/- 11 (PC MRA) versus 85 +/- 15 cm/sec (TCD) after AZM administration. The increase in mean flow velocity (before vs after AZM), that is, the CVR, was 45 +/- 11% as shown by PC MRA and 39 +/- 14% as shown by TCD. Although significant differences were present between the mean flow velocities measured before and those after AZM administration, as determined by PC MRA and TCD, the CVR was not significantly different (45 vs 39%, respectively). These preliminary results suggest that PC MRA may be a method for determining CVR.

Amyloidosis and pleural disease.

Pleural involvement with systemic amyloidosis has been reported rarely in the literature. Diagnosis of this entity by percutaneous needle biopsy of the pleura has been described only in two prior case reports. We describe five patients in whom the diagnosis of pleural amyloidosis was established by Cope needle biopsy during evaluation of pleural effusions of indeterminate cause. Three patients presented with a history suggestive of multiorgan disease and a pleural biopsy performed despite a transudative effusion demonstrated amyloid infiltration of the pleura, obviating the need for other organ biopsies. We conclude that in patients with pleural effusions, if history suggests multiorgan involvement and there is suspicion for amyloidosis, then a closed pleural biopsy with special stains for amyloid should be performed even if the effusions are transudative. This may be the diagnostic procedure of choice in such patients.

[Anatomy of extraoral block anesthesia of the maxillary nerve (precoronoid approach)]. / Contribuição anatômica para a anestesia troncular extra-oral do nervo maxilar (via pré-coronoidea).

The authors measured with sliding-calliper of 0.01 mm of accuracy bi-zigio distance and the distance between the foramen rotundum and vertex of the angle formed by the anterior border of the coronoid process with the lower border of the zygomatic bone. The sample was 160 brazilian adults skulls (50% male and 50% female). Using the Pearson's correlation they found the following results: 1) The positive correlation was reasonably strong in male at the right side between the maximal width of the face and the ideal depth, to reach with an injection needle, the maxillary nerve in the pterigopalatine fossa. 2) The correlation was moderately positive in male sex at the left side and in female at both sides. The formula of the line of regression found was: [table: see text]

[Anatomical variations in the hypoglossal canal]. / Contribuição ao estudo das variações anatômicas do canal do hipoglosso.

In this paper, 492 human dried skulls grouped according to sex and race (White and no White) were examined and the presence of a double hypoglossal canal was observed in 97 skulls. The statistical analysis allowed us to conclude that no significative difference exists in race X canal type; sex X canal type; race X side and sex X side interations.

Endobronchial Mycobacterium avium-intracellulare infection in a patient with AIDS.

The pulmonary manifestations of AIDS are well described in the medical literature; however, MAI infection presenting as an endobronchial lesion has not, to our knowledge, been reported in a patient with AIDS. We report a unique case of an AIDS patient who developed endobronchial polypoid lesions secondary to MAI infection. Complications resulting from these lesions included hemoptysis and later bronchiectasis.

A morphometrical study of human fetal thymus.

A morphometrical study was made of the thymus lobules in the cortical and medullary layers of male and female fetuses, 16 to 31 weeks old, divided into the age groups 16 to 19, 20 to 23, 24 to 27 and 28 to 31 weeks of intrauterine life. Results were correlated with body and thymus weights; the lobular, cortical and medullary volumes, as obtained using a histometrical method, were proportional to thymus, but not body weight increase. No differences were noted in the volumes and weights investigated as a function of fetal sex.

[Turner's syndrome and pregnancy]. / Syndrome de Turner et grossesse.

After briefly summarizing Turner's syndrome, the authors reviewed several cases reported in the literature where pregnancy occurred in association with this syndrome. From this study it was revealed that pregnancy is exceptional in the course of Turner's syndrome since only 2 p. cent of women with this disorder conceive. Such an outcome may be explained by a reduced number of ovarian follicles. The poor prognosis when pregnancy does occur is represented by a 38 p. cent incidence of miscarriage, and an 18.4 p. cent rate of fetal malformations including a 6 p. cent rate of trisomy 21 (Down's syndrome). This finding requires that the patient be taken care of in a specialized department of obstetrics-gynecology, necessitates prenatal diagnosis and poses an ethical problem as to the obstetrical future of these patients.

Vertical migration of the rice white-tip nematode, Aphelenchoides besseyi.

In the laboratory, the vertical migration of Aphelenchoides besseyi was favored by rough surfaces and an inverse water gradient. In relation th gravity, the nematode migrated down or up equally, a circumstance suggesting that a geotaxis was not involved. Stems of rice seedlings were effective surfaces for vertical migration of nematodes only when the stems were continuously supplied with moisture.