Enantioselective Hydrogenation of Ethyl Benzoylformate,from Mechanism and Kinetics to Continuous Reactor Technology

The enantioselective hydrogenation of ethyl benzoylformate over (?)-cinchonidine (CD)-modified Pt/Al₂O₃ catalyst in semi-batch and continuous fixed bed reactors was studied as a function of the modifier concentration and reaction temperature. The kinetic results from the semibatch reactor showed a higher enantioselectivity and lower initial rate as the amount of modifier was increased. The results from the fixed bed reactor demonstrates that continuous enantioselective hydrogenation is possible and that continuous feeding of (?)-CD is needed to maintain a high steady-state enantioselectivity.     

Analysis of delay mean and variance of collision-free WDM rings with segment recirculation of blocked traffic

In Tunable-Transmitter Fixed-Receiver (TT-FR)-based Wavelength Division Multiplexed (WDM) ring topologies, each node is provided with a dedicated wavelength (home channel) for reception, which must be shared by the upstream nodes willing to communicate with it. Thus, to avoid channel collisions, it is necessary to define a Medium Access Control (MAC) mechanism that arbitrates access to a given destination wavelength. This work proposes and analyses a simple MAC mechanism that avoids channel collisions by recirculating traffic on the upstream ring segment where congestion was detected. Essentially, whenever a given node has got any traffic to transmit, it must first block access to in-transit traffic, which is reflected back to the upstream node over a second optical fibre. Such blocked traffic is given a second chance to pass through the congested node after a round segment delay, thus making use of the ring topology as buffering units. This work analyses the performance operation of such a MAC protocol under two policies applied to recirculated traffic: (1) recirculation bypass and (2) recirculation store-and-forward.     

Comparative analysis of breast cancer contamination in mobilized and nonmobilized hematopoietic grafts

We report a case of an 18-month-old female who presented with three supernumerary upper limbs of varying lengths on the right side. Each limb had a proximal, middle, and distal segment, and an intercalated elbow and wrist joint. A single digit was present in the superior limb, three digits in the middle limb, and two digits in the caudal-most limb. Right plagiocephaly, congenital torticollis, scoliosis involving the upper and mid thoracic region, and a hypoplastic right pectoralis major were the other abnormal features noted. Radiography showed two scapulae, humerus, a single forearm bone in each limb, and rudimentary metacarpals and phalanges. Limb duplication may rarely be encountered in parasitic conjoined twins. The role of mutagens, drugs, cellular contributions, and morphogens in the growth and differentiation of limbs has been studied in animals. It is rather difficult to deduce the time of action of the factors responsible for such a malformation.     

Mechanisms, diagnosis, and treatment of diastolic heart failure

Diastolic heart failure, in the absence of LV systolic dysfunction, is a common clinical condition that can be demonstrated in as many as one third of patients with congestive heart failure. Diastolic dysfunction caused by abnormalities in LV filling can be a result of many pathologic conditions, including hypertrophy, infiltrative cardiomyopathies, or myocardial ischemia. The major physiologic determinants of LV filling can be divided into cellular mechanisms, hemodynamic characteristics, and hormonal influences. Cellular mechanisms for impaired LV inactivation are determined by the handling of calcium within the myocyte during excitation-contraction-relaxation coupling. The hemodynamic characteristics of LV diastolic filling are determined by loading conditions, the time constant of isovolumic relaxation, heart rate, ventricular nonuniformity, pericardial restraint, myocardial elasticity, chamber compliance, and coronary blood flow. The sympathetic nervous system and the renin-angiotensin system are important modulators of diastolic filling, directly or indirectly. The diagnosis of heart failure is confirmed by a combination of clinical tests including invasive and noninvasive techniques, each of which has advantages and disadvantages. Treatment of medical conditions in which diastolic heart failure is a prominent component include pharmacotherapy with calcium channel antagonists, beta-adrenergic blocking agents, diuretic agents, and angiotensin-converting-enzyme inhibitors. Certain conditions associated with diastolic filling abnormalities such as pericardial disease or severe ischemic heart disease may be best managed by surgical or percutaneous intervention. Future research will include further delineation of the cellular mechanisms of active myocardial relaxation and clinical investigation into treatment directed at improving outcome.     

Technicians or physicians

PURPOSE: To present an unusual case of a preretinal mass that simulated a retained metallic foreign body. METHOD: Case report. RESULTS: A 30-year-old man presented with unilateral iridocyclitis and an ipsilateral preretinal mass with ultrasonographic and computed tomographic characteristics of a metallic foreign body. Histologic examination of the mass disclosed a central concentration of iron-containing hemoglobin breakdown products surrounded by a cocoon of fibrous tissue. CONCLUSION: Blood breakdown products surrounded by a fibrous capsule can present with the characteristics of an intraocular metallic foreign body.     

Carmustine and streptozocin in refractory melanoma: an attempt at modulation of O-alkylguanine-DNA-alkyltransferase

The activity of the enzyme O6-alkylguanine-DNA-alkytransferase (AGAT) protects cells from the cytotoxic effects of alkylating agents. This Phase II trial was designed to assess the efficacy of a strategy designed to modulate the resistance to carmustine (BCNU) mediated by AGAT using streptozocin (STZ) in patients with advanced refractory melanoma. Seventeen patients who had failed prior chemotherapy were treated with STZ at 500 mg/m2 daily for 4 days with BCNU at 150 mg/m2 on day 3. Peripheral blood lymphocytes for assay of AGAT activity levels were collected prior to therapy and following the third dose of STZ. There were two partial responses in the 15 patients evaluable for response (13%). Most patients received only a single cycle of therapy due to rapidly progressive disease. Two patients developed fatal pulmonary toxicity, and one developed myelodysplasia. Other toxicities included transient rises in liver function tests. AGAT levels decreased by a mean of 53% in 9 patients but actually increased over baseline in 3 patients while on therapy. Based on these data, BCNU and STZ are not an effective combination for the therapy of advanced refractory melanoma, and pulmonary toxicity due to this combination appears to be increased compared with BCNU alone. STZ is not an effective modulator of AGAT activity when given on this schedule. New strategies designed to deplete AGAT activity using O6-benzylguanine or temozolomide should be explored with careful attention to the possibility that this approach may potentiate both the toxicity and efficacy of BCNU.     

Surface quality in milling of hardened H13 steel

In the final milling process of free-form surfaces, commonly employed in the production of molds and dies, knowledge of the cutting conditions and a strategy for choosing adequate processing routes can provide a significant reduction in the manufacturing times. The objective of this work is to evaluate quantitatively and qualitatively the surface quality behavior of a steel used in the production of dies and molds. The analysis was carried out for hardened AISI H13 tool steel inclined at an angle of 60° and for different cutting path orientations. The roughness of milled surfaces was measured and verified by scanning electron microscopy in order to compare the strategies and the surface textures obtained. Four different cutting path strategies were employed in these experiments, with horizontal and vertical single-direction rastering, both upward and downward. The conclusion is that, in the vertical upward strategy, the surface displays greater roughness and an irregularity with regard to plastic deformation. The other strategies showed lower roughness and similar regularity. Magnetic Barkhausen noise, used for sub-surface characterization, was found to be largest when measured along the cutting direction of the inserts. These directions coincided with the directions of greatest plastic deformation in the sub-surface region.     

Storage of green coffee in hermetic packaging injected with CO2

The objective of this study was to evaluate the physical, chemical, and sensory qualities of green coffee beans (Coffea arabica L.) during storage in different types of packaging. Coffee was stored from October 2008 to September 2009 in a warehouse of the Agriculture Society Ltda. (SAAG) in Santana da Vargem, southern Minas Gerais State, Brazil. The treatments in the factorial design consisted of two types of packaging (hermetic big bags with the injection of up to 60% CO₂ in a controlled atmosphere; similar bags but without the injection of CO₂ in a modified atmosphere) and three sampling positions in the bags (high, medium, and low). At 3-month intervals during a 12-month period, grains were analyzed to determine their water content, color, electrical conductivity, potassium lixiviation, and content of sugars. Sensory analysis was also conducted at these sampling times. The storage of green coffee beans in hermetic big bags on a commercial scale under modified and controlled atmospheric conditions is viable over a 12-month period. The coffee packed in big bags maintained its quality and exhibited an intensification of the green coloration of the grains during storage. Sensory analysis of coffee beans stored in a controlled atmosphere showed that the medium sampling position yielded the best ratings. The results of this analysis demonstrated that this storage technique can potentially increase the effectiveness of methods used to preserve the sensory quality of coffee beans.     

Transfer learning by mapping and revising boosted relational dependency networks

Machine Learning - Statistical machine learning algorithms usually assume the availability of data of considerable size to train the models. However, they would fail in addressing domains where...     

Comparative B‐mode and Doppler renal ultrasonography with histopathological findings in dogs positive for canine visceral leishmaniasis

Morphological parameters and renal flow were assessed and measured in six clinically healthy dogs with negative serological and parasitological examinations for canine visceral leishmaniasis (CVL) and six dogs with CVL‐positive serological and parasitological tests and asymptomatic condition of the disease. Kidney length and diameter were measured and compared with the aorta/kidney ratio. Alterations in flow were measured using the flow velocity (cm/s) and resistance index (RI). Renal function was assessed by serum biochemical examination (urea, creatine, total proteins, albumin, and globulin) and urinalysis. CVL‐positive animals presented heterogeneous kidney echotexture, reduced vascular flow, hypoperfusion, lesser visualization of the arcuate arteries, high RI values (1.06 ± 0.28 for the right kidney and 1.10 ± 0.30 for the left kidney), reduced diastolic flow, and high systolic peak. They also presented positive creatine/RI correlation and between the renal artery vascular flow and kidney diameter. Histopathological analysis of CVL‐positive animals was compatible and confirmed hemodynamic changes observed by Doppler ultrasound. The findings in the present study showed that Doppler ultrasonography is a valid method to assess and detect alterations in flow in renal pathological processes with kidney vascular damage, as in the case of leishmaniasis, and can help in the diagnosis of animals with this infection. Microsc. Res. Tech. 79:637–645, 2016. © 2016 Wiley Periodicals, Inc.