Cystic fibrosis in Malay children--a report of three cases

A staining device for sectioned material supported on grids for viewing at the Transmission Electron Microscope is described. The method based in a double side sticky tape is inexpensive, rapid and clean. By using only pipettes and a double side sticky tape the best solution to the tedious problems of sections staining is obtained. The tape is discarded and the staining solution too. Precipitates have not been observed.     

Analysis of the Mechanical Stability of Boreholes Drilled in Sedimentary Rocks

This article presents the method and results of wellbore stability analysis for three common reservoir lithologies consisting of a consolidated sandstone, a shaly sandstone, and a limestone formation. The effect of stress anisotropy on the mechanical stability of wellbores is evaluated while varying the inclination angle from 0 to 90°, for both the Mohr-Coulomb and the Drucker-Prager failure criteria. The selected failure criterion, and the in-situ rock stress regime are found to have significant effects on the safe drilling fluid density required to maintain wellbore integrity. According to some field examples, the Drucker-Prager failure criterion appears to systematically mimic rock conditions more realistically than the Mohr-Coulomb failure criterion. The simulated consolidated sandstone formation is found more stable with lesser drilling fluid density, at any inclination angle, than the simulated shaly sandstone formation. The simulated limestone formation is even more stable than the consolidated sandstone at all inclination angles since it requires lighter fluid density to prevent wellbore collapse. For all these rock types, the higher the deviation angle (from vertical), the higher the drilling fluid density needed for maintaining wellbore integrity. For the depth and rock conditions simulated, both consolidated and shaly sands are unstable in a strike-slip stress regime, but stable in an extensional stress regime. The simulated limestone formation was found stable in both stress regimes. However, in an extensional stress regime, the limestone formation required lighter fluid density to maintain wellbore integrity than in a strike-slip stress regime. This article introduces the theory of using a practically-oriented model to assess the mechanical stability of a wellbore in a linearly-elastic stress field. The model can be used to determine the range of mechanically stable well inclinations for a given formation, and to suggest drilling-fluid density programs tailored to efficient and safe drilling.     

Anti-GBM glomerulonephritis in mice lacking nitric oxide synthase type 2

To determine the relationship between quantitative Doppler parameters of portal, hepatic, and splanchnic circulation and hepatic venous pressure gradient (HVPG), variceal size, and Child-Pugh class in patients with alcoholic cirrhosis, we studied forty patients with proved alcoholic cirrhosis who underwent Doppler ultrasonography, hepatic vein catheterization, and esophagoscopy. The following Doppler parameters were recorded: time-averaged mean blood velocity, volume flow of the main portal vein flow, and resistance index (RI) of the hepatic and of the superior mesenteric artery. Doppler findings were compared with HVPG, presence and size of esophageal varices, and Child-Pugh class. There was a significant inverse correlation between portal velocity and HVPG (r = -.69), as well as between portal vein flow and HVPG (r = -.58). No correlation was found between RI in the hepatic artery or superior mesenteric artery and HVPG. No correlation was found between portal vein measurements and presence and size of varices. Severe liver failure was associated with lower portal velocity and flow. In patients with alcoholic cirrhosis, only portal vein blood velocity and flow, but neither hepatic nor mesenteric artery RI, are correlated to the severity of portal hypertension and to the severity of liver failure.     

Therapeutic approach in arterial hypertension with renal artery stenosis

Screening for renal artery stenoses in hypertensive patients aims at detecting lesions whose treatment (renal revascularization) will normalize or reduce blood pressure and correct or prevent reduced glomerular filtration. Consequently, screening tests such as renal artery duplex Doppler scanning, renal scintigraphy or digital-subtraction angiography are used in patients in whom hypertension is severe, drug-resistant or associated with renal failure. Surgical repair or transluminal angioplasty is not warranted for all stenoses, however, particularly in atheromatous stenoses where these procedures have a 1% mortality, a 10% morbidity and a 30% failure rate to improve blood pressure despite adequate anatomical outcome. Predictors of favourable blood pressure outcome following revascularization are aetiological (fibrous dysplasia rather than atheroma), historical (young age, short duration of hypertension), physiological (renal ischaemia confirmed by scintigraphy, lateralizing renal vein renin ratio) and anatomical (truncal rather than ostial or branch stenoses). Outcome of surgery and transluminal angioplasty has only been documented in retrospective, uncontrolled reports in which blood pressure improvement is overestimated via the placebo effect, habituation to blood pressure readings and optimization of drug treatment, the latter being frequently required despite adequate revascularization. The first prospective randomized trials evaluating angioplasty in atheromatous stenoses are underway and should provide objective information concerning the risk/benefit ratio of this procedure.     

Solving partial differential equations of gas–solid reactions by orthogonal collocation

In this work the solution of the coupled partial differential equations for noncatalytic gas–solid reactions has been considered by orthogonal collocation. First of all, by an integral transformation and then by applying the orthogonal collocation method, these partial differential equations are converted to the ordinary differential equations. Then the equations are solved and the conversion–time profiles are obtained. The solution of the equations for volume reaction model, grain model and grain model with product layer resistance, modified grain model, random pore model, nucleation model and reaction of two gas with one solid has been presented in this work. The orthogonal collocation is a rapid method for solving of these equations and shows a good accuracy with respect to other solution techniques in the literature.     

Phytochemical composition of the essential oils from three Apiaceae species and their antibacterial effects on food-borne pathogens

Essential oils (EOs) of three Apiaceae species, including Bunium persicum, Cuminum cyminum and Carum copticum, extracted by hydrodistillation, were analyzed by gas chromatography (GC) and GC/mass spectrometry. The main components of EOs of B. persicum were γ-terpinene (44.2%), cuminaldehyde (16.9%), γ-terpinen-7-al (10.5%), and ρ-cymene (8%). The major constituents of Cu. cyminum were cuminaldehyde (30.2%), ρ-cymene (14.1%), γ-terpinene (12.8%), and safranal (9.4%), while those of Ca. copticum were thymol (48.4%), ρ-cymene (21.8%) and γ-terpinene (21.3%). The antibacterial effects of the EOs were assessed on several food-borne pathogens, namely Staphylococcus aureus, Bacillus cereus, Escherichia coli O157:H7, Salmonella enteritidis, and Listeria monocytogenes. The ranges of minimum inhibitory concentration (MIC) of the oils were 0.03–0.5, 0.18–3.0, and 0.37–3.0 mg/ml, respectively, for Ca. copticum, B. persicum and Cu. cyminum. Moreover, the combination of B. persicum and Cu. cyminum EOs confirmed synergistic and additive activities against the pathogens.     

Effect of microencapsulation and resistant starch on the probiotic survival and sensory properties of synbiotic ice cream

Two types of synbiotic ice cream containing 1% of resistant starch with free and encapsulated Lactobacillus casei (Lc-01) and Bifidobacterium lactis (Bb-12) were manufactured. The survival of L. casei and B. lactis were monitored during the product’s storage for 180 days at −20 °C. The viable cell number of L. casei and B. lactis in the free state in prepared ice cream mixture was 5.1 × 10⁹ and 4.1 × 10⁹ CFU/mL at day one and after 180 days storage at −20 °C, these numbers were decreased to 4.2 × 10⁶ and 1.1 × 10⁷ CFU/mL, respectively. When we encapsulated the mentioned probiotic bacteria in calcium alginate beads, the probiotic survival raised at rate of 30% during the same period of storage at same temperature. In general, the results indicated that encapsulation can significantly increase the survival rate of probiotic bacteria in ice cream over an extended shelf-life. The addition of encapsulated probiotics had no significant effect on the sensory properties of non-fermented ice cream in which we used the resistant starch as prebiotic compound.     

Preformed particle gels of sulfonated polyacrylamide: preparation,characterization, and application as permeability modifier

In this study, a preformed particle gel (PPG) was synthesized from sulfonated polyacrylamide and chromium metal cross-linker with specific concentration. The main characteristics of PPG, such as gelation time, gel fraction, swelling properties and salt sensitivity factor were investigated. The gel fraction of 94.1% practically indicated an appropriate conversion of gelant to the gel. The equilibrium swelling ratios of particle gels in distilled water and formation water at 80 °C were 470.49 and 12.61, respectively. Additionally, the rheological properties of gel were studied by a dynamic rheometer. The ultimate storage modulus of gel was measured 35.4 kPa. The linear viscoelastic behavior was observed at strain between 1 and 82.6% and gel structure was stable up to strain of 1120% with small reduction of storage modulus. The kinetics of gelation were also studied at different temperatures and tested against Avrami equation to determine the kinetic parameters. The Avrami exponents for two kinetic steps were about 2.29 and 0.80, respectively, indicating the rapid formation of the gel network at first step due to nucleation and two-dimensional growths of gel nuclei. Furthermore, a core flooding experiment was conducted to study PPG performance in porous media. The residual resistance factor of water and oil was 41.58 and 12.91, respectively. A value of 3.22 for the ratio of these two factors indicated the ability of the synthesized PPG to decrease water-effective permeability compared to oil-effective permeability in porous media.