Study on percutaneous rate of P-aminobenzoates using molecular orbital method

The use of a dome osteotomy in the treatment of infantile tibia vara is reportedly associated with insufficient intraoperative assessment of the correction achieved. This article discusses a method to overcome this problem and the long-term advantages of using a dome osteotomy in the treatment of this disease.     

N-(2-Benzoylphenyl)-L-tyrosine PPARgamma agonists. 3. Structure-activity relationship and optimization of the N-aryl substituent

3-?4-[2-(Benzoxazol-2-ylmethylamino)ethoxy]phenyl?-(2S)-((2- benzoylph enyl)amino)propionic acid (1) and (2S)-((2-benzoylphenyl)amino)-3-?4-[2-(5-methyl-2-phenyloxazol-4-y l)e thoxy]phenyl?propionic acid (2) are peroxisome proliferator-activated receptor gamma (PPARgamma) agonists and have antidiabetic activity in rodent models of type 2 diabetes. As part of an effort to develop the SAR of the N-2-benzoylphenyl moiety of 1 and 2, a series of novel carboxylic acid analogues, 23-66, modified only in the N-2-benzoylphenyl moiety were synthesized from L-tyrosine and evaluated as PPARgamma agonists. In general, only modest changes in the N-2-benzoylphenyl moiety of 1 and 2 are tolerated. More specifically, the best changes involve bioisosteric replacement of one of the two phenyl rings of this moiety. Addition of substituents to this moiety generally produced compounds that are less active in the cell-based functional assays of PPARgamma activity although binding affinity to PPARgamma may be maintained. A particularly promising set of analogues is the anthranilic acid esters 63-66 in which the phenyl ring in the 2-benzoyl group of 1 and 2 has been replaced by an alkoxy group. In particular, (S)-2-(1-carboxy-2-?4-[2-(5-methyl-2-phenyloxazol-4-yl)ethoxy]phen yl? ethylamino)benzoic acid methyl ester (63) has a pKi of 8.43 in the binding assay using human PPARgamma ligand binding domain and a pEC50 of 9.21 in the in vitro murine lipogenesis functional assay of PPARgamma activity. Finally, 63 was found to normalize glycemia when dosed at 3 mg/kg bid po in the Zucker diabetic fatty rat model of type 2 diabetes.     

Metastasis of carcinoma of cervix uteri to convexity meningioma

A cerebral collision tumor in which a convexity meningioma was invaded by a metastatic squamous cell carcinoma of the cervix uteri is described. This is the first time such a lesion has been reported to invade a cerebral meningioma. The patient lived three active years postoperatively until the lesion recurred. Her status then deteriorated, and she died five years after the operation. This was a longer follow-up than any among the other 17 cases of carcinomatous metastases to meningiomas found in the literature.     

Images of finite sized spherical particles in confocal and conventional microscopes when illuminated with arbitrary polarization

We investigate the form of the image of a finite sized spherical particle in confocal and conventional microscopes when the illuminating light has an arbitrary polarization. In particular, we take the cases of radial and azimuthal polarizations and use the Mie theory to find the scattered field from differently sized particles for these cases. We present numerical results for the changes in the detected intensity when subresolution and resolvable spherical particles are illuminated with particular wavelengths and polarizations. Further, we find the limiting size of a particle for which it can be considered a point scatterer for a particular wavelength.     

Assessment of thermal performance improvement of GT-MHR by waste heat utilization in power generation and hydrogen production

The Gas Turbine Modular Helium Reactor (GT-MHR) uses two compression stages to compress the helium and a pre-cooler and an intercooler to reduce the compressors inlet temperature, that dissipate around 308.36 MW_th at the design operational conditions. This dissipated thermal energy can be used as an energy source to produce hydrogen. An energy analysis is conducted for a proposed system that includes GT-MHR combined with Organic Rankine Cycle (GT-MHR/ORC) and a Proton Exchange Membrane (PEM) electrolyzer (GT-MHR/ORC-PEM) for hydrogen production. The optimum operating parameters values of the new cycle are obtained using the Engineering Equation Solver (EES) software. Thermal efficiency has been improved from 48.6% for the simple GT-MHR cycle to 49.8% for the new combined (GT-MHR/ORC-PEM) cycle including hydrogen production at a rate of 0.0644 kg/s at the same operating conditions. However, the thermal efficiency for the combined GT-MHR/ORC was higher and reaches 50.68%. Moreover, a parametric study is carried out over a wide range of some operating conditions such as turbine inlet temperature, Compressor pressure ratio and compressor inlet temperature to investigate their effect on the new cycle performance. Results revealed that increasing the low-pressure compressor inlet temperature increases the amount of hydrogen produced while decreasing thermal efficiencies for the three cycles. Furthermore, increasing compressor pressure ratio reduces the mass flow rate of hydrogen produced util it reaches a minimum value then it starts to increase slightly, on the contrary, an opposite relationship is observed between thermal efficiencies and compressor pressure ratio. Moreover, at low compressor pressure ratio, the rate of hydrogen produced increases with increasing turbine inlet temperature; however, it decreases by increasing the turbine inlet temperature at high compressor pressure ratio. Nevertheless, a direct correlation is noticed between thermal efficiencies and turbine inlet temperature.     

Shape-memory nitinol alloy endoprosthesis for malignant biliary strictures

A new design of endoprosthesis, made of shape-memory nitinol alloy, was used to replace the currently used one, which was soon clogged with bile mud. After nitinol wire coil stent was slenderized in ice water, it was inserted into the strictured bile duct by endoscopy or operation. When nitinol wire coil was positioned in a narrowed biliary segment, normal saline heated to 39 degrees C was rapidly hand-injected into the lumen of the inner transport catheter to make the alloy coil to resume its original shape with a length of 3 to 10cm, and a diameter of 5 to 10mm. Since June 1991, 13 patients with malignant biliary strictures were treated with nitinol endoprosthesis. The follow-up period ranged from 1 to 16 months (average 6 months). Biliary sludge was not found in the endoprosthesis during the period. The results suggested that shape-memory nitinol alloy endoprosthesis could maintain long term patency without severe infection or obstruction due to biliary sludge.     

(2,4-cis and trans)-gigantecinone and 4-deoxygigantecin, bioactive nonadjacent bis-tetrahydrofuran annonaceous acetogenins, from Goniothalamus giganteus

Two new acetogenins, (2,4-cis and trans)-gigantecinone (1), isolated as a mixture, and 4-deoxygigantecin (2), a known acetogenin whose absolute stereochemistry has not been determined previously, were isolated using activity-directed fractionation, from the bark of Goniothalamus giganteus. A key step in solving their absolute stereochemistries was the preparation of 1,4-diol formaldehyde acetal derivatives (1b and 2a). Using the advanced Mosher ester method and circular dichroism, the absolute stereochemistries of 1 and 2 were revealed and were found to be the same as that of gigantecin (3), which supports a common biogenetic origin. Both 1 and 1b showed potent and selective cytotoxicities against the PC-3 human prostate adenocarcinoma cell line. Against yellow fever mosquito larvae, 1 and 2 were more potent than rotenone in pesticidal activity. Longimicin C and a mixture of (2,4-cis and trans)-isoannonacin were also isolated for the first time from this species.     

Impact of erythromycin on respiratory colonization of Ureaplasma urealyticum and the development of chronic lung disease in extremely low birth weight infants

BACKGROUND: Chronic lung disease (CLD) is a significant cause of neonatal morbidity and mortality despite advances in neonatal care. Ureaplasma urealyticum colonization of the lower respiratory tract has been associated with CLD, particularly in extremely low birth weight infants. Despite numerous studies demonstrating the pathogenicity of this organism, treatment remains controversial. This study examines neonates colonized with U. urealyticum in the lower respiratory tract and treated with erythromycin, as compared with noncolonized neonates. METHODS: A prospective cohort study of 124 neonates weighing <1000 g at birth, requiring endotracheal intubation and ventilation. Endotracheal aspirates were cultured for U. urealyticum and conventional bacteria twice weekly for the duration of endotracheal intubation. Infants colonized with U. urealyticum were treated with intravenous erythromycin. Maximal ventilatory requirements, CLD at Day 28 and 36 weeks postconception, duration of ventilation, oxygen dependency and hospital stay were documented. RESULTS: Twenty-two infants (18%) were identified as being U. urealyticum colonized in endotracheal aspirates. Colonization was significantly associated with younger maternal age, prolonged rupture of membranes, premature labor and vaginal delivery. Of colonized neonates 14% were delivered by cesarean section, with intact membranes. As compared with noncolonized infants, there were no statistically significant differences in chronic lung disease, duration of oxygen therapy or time to discharge. CONCLUSIONS: Seven published cohort studies of similar high risk populations where U. urealyticum-colonized infants did not receive erythromycin therapy, show a consistent association with CLD (pooled relative risk + 5.21; 95% confidence interval, 2.93 to 9.64). This association was not demonstrated in the current study and adds further weight to the need for a randomized controlled trial to be performed to evaluate this treatment regimen.