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Residual right ventricular outflow obstruction during Tetralogy of Fallot repair necessitates peri-operative revision often requiring trans-annular patch with its negative sequels. Bidirectional Glenn shunt in this setting reduces trans-pulmonary gradient to avoid revision.
Bidirectional Glenn shunt was added during Tetralogy repair in patients with significant residual obstruction. A total of 53 patients between January, 2011 and June, 2018 were included. Final follow-up was conducted in July, 2018.
Mean age at operation was 5.63±3.1 years. Right to left ventricular pressure ratio reduced significantly (0.91±0.09 versus 0.68±0.05; p<0.001) after bidirectional Glenn, avoiding revision in all cases. Glenn pressures at ICU admission decreased significantly by the time of ICU discharge (16.7±3.02 versus 13.5±2.19; p<0.001). Pleural drainage ≥ 7 days was seen in 14 (26.4%) patients. No side effects related to bidirectional Glenn-like facial swelling or veno-venous collaterals were noted. Mortality was 3.7%. Discharge echocardiography showed a mean trans-pulmonary gradient of 32.11±5.62 mmHg that decreased significantly to 25.64±5 (p<0.001) at the time of follow-up. Pulmonary insufficiency was none to mild in 45 (88.2%) and moderate in 6 (11.8%). Mean follow-up was 36.12±25.15 months (range 0.5–90). There was no interim intervention or death. At follow-up, all the patients were in NYHA functional class 1 with no increase in severity of pulmonary insufficiency.
Supplementary bidirectional Glenn shunt significantly reduced residual right ventricular outflow obstruction during Tetralogy of Fallot repair avoiding revision with satisfactory early and mid-term results.
Two experiments were conducted to evaluate the effects of replacing corn with an increasing concentration of high-purity glycerol (>99%) on growth performance, economical efficiency, blood constituents and nutrient digestibility of growing lambs. In experiment one, 24 male lambs (initial BW=33.6±6.0 kg; age=6.75±0.75 months) were randomly assigned to one of the three experimental treatments containing 0%, 5% or 10% glycerol to replace corn in concentrate. In experiment two, nine lambs (initial BW=44.7±2.2 kg, age=8.84±0.32 months) were used in a digestion trial with three treatments (three lambs per treatment) with glycerol replacing corn at 0%, 5% or 10% in the concentrate. Total dry matter (DM) intake decreased quadratically (P=0.003) with increasing concentration of glycerol in the diet. Lambs fed glycerol diets had greater average daily gain (P=0.005) and better feed efficiency (P=0.002) compared with the control. Feed costs were also reduced with glycerol inclusion. Glycerol supplementation did not affect serum concentrations of total protein, albumin, globulin, total lipid, cholesterol and glucose concentrations. Glycerol supplementation had no effect (P>0.05) on organic matter and CP digestion, but improved DM (P=0.0003), crude fiber (P=0.10), ether extract (P=0.0002) and nitrogen-free extract (P=0.05) digestion. In conclusion, glycerol can replace corn up to 10% of DM in the diets of growing lambs.
This study was conducted to evaluate the effect of increasing levels of glycerol in the diet on milk yield and composition, diet digestibility and some blood metabolites of dairy buffaloes in early lactation. A total of 24 buffaloes were blocked by average milk yield, parity and BW and then randomly assigned to three treatments: control without glycerol (CON); low glycerol (LG): control plus glycerol at 150 ml/day per buffalo; and high glycerol (HG): control plus glycerol at 300 ml/day per buffalo. The experimental period lasted for 60 days. Feeding LG and HG decreased (P<0.0001) dry matter intake compared with the CON. Buffaloes supplemented with LG and HG produced more milk (P<0.01) and had a greater (P<0.0001) yield of fat-corrected milk (3.5%) than those buffaloes fed control treatment. Glycerol-supplemented buffaloes showed a positive energy status indicated by reduced concentrations of non-esterified fatty acids and β-hydroxybutyrate. Feeding LG and HG tended to increase (P⩽0.10) concentrations of milk fat, and serum total protein and globulin and significantly decreased (P⩽0.05) milk urea nitrogen and somatic cells counts (SCCs) compared to the CON group. Inclusion of LG and HG had no effect on organic matter and non-fiber carbohydrate digestion, but improved dry matter (P=0.02), CP (P=0.09), ether extract (P=0.03), NDF (P=0.07) and ADF (P=0.03) digestion.
Mechanical properties of the metals and their alloys are influenced by the material grain size at microscale. In the present study, the Johnson-Cook (JC) material model is modified to incorporate the effect of material's grain size along with the plasticity coupled damage model. 2D finite element (FE) simulations of turning process of an aerospace grade aluminium alloy 2024 (AA2024) were performed with different grain sizes using a commercial FE software, ABAQUS/Explicit. FE simulation results were compared with the published experimental data on turning process of AA2024. The proposed modified JC material model successfully simulated the increase in cutting force as a function of grain size refinement.
Dengue has become a global problem in past few decades, with half of the world's population at risk of infection. For some countries of Asia and Latin America, severe dengue is a major cause of serious illness and even death in children. Pakistan has been reported as a hyperendemic area for dengue infection. Our study aimed to find seroprevalence of past dengue infection in asymptomatic children of Lahore with no previous history of dengue infection. A total of 400 samples were collected from children aged 1–12 years in Lahore using random sampling. The inclusion criteria were children aged 1–12 years, who had no previous symptoms of dengue fever during their lives. Children with known immunodeficiency status or fever at the time of recruitment were excluded from the study. Commercially available ELISA kits were used to determine the IgG status in sera of children. The data obtained was entered and analysed using SPSS v. 20.0. The overall prevalence of asymptomatic dengue infection was found to be 25%. There was no statistically significant difference between prevalence of infection in male and female children. There was, however, a strong relationship between increasing age of the child and number of cases with infection, with low incidence in children aged ⩽5 years.
In the Kingdom of Saudi Arabia (KSA), Old World cutaneous leishmaniasis (CL) is mainly caused by Leishmania major and Leishmania tropica parasites. Diagnosis of CL is predominately made by clinicians, who at times fail to detect the disease and are unable to identify parasite species. Here, we report the development of a chemiluminescent enzyme-linked immunosorbent assay (CL-ELISA) to measure the levels of anti-α-galactosyl antibodies in human sera. Using this assay, we have found that individuals infected with either Leishmania spp. had significantly elevated levels (up to 9-fold higher) of anti-α-Gal IgG compared to healthy control individuals. The assay sensitivity was 96% for L. major (95% CI; 94–98%) and 91% for L. tropica (95% CI; 86–98%) infections and therefore equivalent to restriction fragment length polymorphism-polymerase chain reaction analysis of parasite ITS1 gene. In addition, the assay had higher sensitivity than microscopy analysis, which only detected 68 and 45% of the L. major and L. tropica infections, respectively. Interestingly, up to 2 years following confirmed CL cure individuals had 28-fold higher levels of anti-α-Gal IgG compared to healthy volunteers. Monitoring levels of anti-α-Gal antibodies can be exploited as both a diagnostic tool and as a biomarker of cure of Old World CL in disease elimination settings.
For qualitative prediction of chip morphology and quantitative prediction of burr size,
2D and 3D finite element (FE) based turning models have been developed in this paper.
Coupled temperature-displacement machining simulations exploiting the capabilities of
Abaqus® with a particular industrial turning insert and a newly proposed geometrical
version of this insert have been performed. Limitations of 2D models in defining the chip
morphologies and surface topologies have been discussed. The phenomenological findings on
the Poisson burr (Side burr) formation using 3D cutting models have been highlighted.
Bespoke geometry of the turning insert has been found helpful in reducing the Poisson burr
formation, as it reduces the contact pressures at the edges of tool rake face-workpiece
interface. Lower contact pressures serve to decrease the material flow towards workpiece
edges (out of plane deformation). In contrast, higher contact pressures at tool rake
face-workpiece interface lead to more material flow towards workpiece edges resulting in
longer burr. Simulation results of chip morphologies and cutting forces for turning an
aluminum alloy A2024-T351 have been compared with the experimental ones. Finally, it has
been concluded that the newly proposed geometry of the insert not only decreases the burr
but also helpful in lessening the magnitude of tool-workpiece initial impact.
Achai is an as yet undocumented but well-adapted cattle breed of the Hindu Kush Mountains of northern Pakistan, which is reared under sedentary farming system (SFS) and transhumant farming system (TFS). This paper compares the morphological (physical and morphometric) characteristics of this cattle breed under both farming systems to know the effect of these styles of management. Data were collected from 108 adult females and 108 males in SFS and 108 females and 36 males in TFS on physical characteristics (colour of the coat, horns, eyelashes, muzzle, hoof, switch) and morphometric measurements – i.e. heart girth, body length, height at withers, height at hipbone, face length, horn length, horn circumference, ear (length and width), neck length, dewlap length, chine length, loin length, rump (length and width), length below knee, hoof circumference, tail and switch length. Results showed that farming systems significantly affect most of the morphological characteristics of both sexes, particularly the morphometric measurements with tall and leggy conformation for TFS cows and bulls. This indicates an adaptation to long distance transhumance and mountain terrain grazing. It can be concluded that the Achai has the potential to adapt to the requirements of specific farming systems. There is hence a need for the conservation of its adaptive traits in both farming systems.
This study aims to characterize Azikheli, an undocumented buffalo breed, in its home tract (Khwazakhela, Swat, Pakistan) under traditional farming conditions. For this purpose, 108 buffalo cows and 27 bulls were randomly selected. Mean, standard error, Student's t test and Chi-square test were used for various comparisons. The results show that the majority of animals have a brown coat colour. Cows have significantly higher heart girths, longer horns, longer necks and wider faces at the level of the eyes than bulls, whereas bulls have significantly longer bodies, longer ears, thicker horns, thicker necks and larger hooves than cows. Horns are flat laterally, directed backwards and then slightly upwards without twisting, leading to a sickle to semi-sickle appearance. Owing to its small body size and brown coat colour, the breed is well adapted to mountain slope grazing and thrives well away from swamps. Its adaptation to mountainous ecosystems warrants its in situ conservation.
Exclusive breast-feeding is estimated to reduce infant mortality in low-income countries by up to 13 %. The aim of the present study was to determine the risk factors associated with suboptimal breast-feeding practices in Pakistan.
A cross-sectional study using data extracted from the multistage cluster sample survey of the Pakistan Demographic and Health Survey 2006–2007.
The prevalences of timely initiation of breast-feeding, bottle-feeding in children aged 0–23 months, exclusive breast-feeding and predominant breast-feeding in infants aged 0–5 months were 27·3 %, 32·1 %, 37·1 % and 18·7 %, respectively. Multivariate analysis indicated that working mothers (OR = 1·48, 95 % CI 1·16, 1·87; P = 0·001) and mothers who delivered by Caesarean section (OR = 1·95, 95 % CI 1·30, 2·90; P = 0·001) had significantly higher odds for no timely initiation of breast-feeding. Mothers from North West Frontier Province were significantly less likely (OR = 0·37, 95 % CI 0·23, 0·59; P < 0·001) not to breast-feed their babies exclusively. Mothers delivered by traditional birth attendants had significantly higher odds to predominantly breast-feed their babies (OR = 1·96, 95 % CI 1·18, 3·24; P = 0·009). The odds of being bottle-fed was significantly higher in infants whose mothers had four or more antenatal clinic visits (OR = 1·93, 95 % CI 1·46, 2·55; P < 0·001) and belonged to the richest wealth quintile (OR = 2·41, 95 % CI 1·62, 3·58; P < 0·001).
The majority of Pakistani mothers have suboptimal breast-feeding practices. To gain the full benefits of breast-feeding for child health and nutrition, there is an urgent need to develop interventions to improve the rates of exclusive breast-feeding.
We describe novel 2-D structures that facilitate strain relief and allow us to obtain Ge epilayers that are free of defects. These structures can potentially absorb thermal expansion and lattice expansion mismatch as well as enable liftoff of heteroepitaxial layers for subsequent wafer reuse. Conventional lithography techniques were combined with reactive ion and wet-chemical etching to fabricate 2-D patterns of silicon posts. The dimensions of the posts were varied keeping the pitch (center to center distance) constant. Heteroepitaxial growth of Ge/SixGe1−x on these micrometer-scale structures was investigated. While, keeping the growth parameters constant, the geometry of the structures was varied to determine the optimum configuration for the highest quality heteroepitaxial growth. The quality of the Si1−xGex buffer system was investigated using high-resolution x-ray diffraction. Transmission electron microscopy (TEM) was used to analyze the epilayer cross-sections. Surface morphology was analyzed using scanning electron microscopy (SEM), atomic force microscopy (AFM) and optical microscopy. Our results show that the quality of the heteroepitaxial layers improves as the width of the posts in the 2-D pattern was decreased.
Observations of efficient room temperature photoluminescence (PL) from porous Si have generated a great deal of interest in the optical properties of nm-scale Si structures. The stochastic character of porous-Si fabrication results in a distribution of crystal sizes and shapes. We report on a scalable (to large areas) and manufacturable (to high volumes) fabrication technology for uniform, nm-linewidth Si structures providing an important testbed for controlled studies of these optical properties. Large areas ( ∼ 1 cm2) of extreme sub-μm structures (to ∼ 5 nm) are re-producibly fabricated. Both walls (1-D confinement) and wires (2-D confinement) are reported. The fabrication process includes: interferometric lithography, highly anisotropic KOH etching, and structure dependent oxidation. For the walls, nearly perfect <111> crystal planes form the sidewalls and very high width/depth aspect ratios (> 50) have been achieved. Raman scattering results on the walls demonstrate three regimes: 1) lineshapes and cross sections similar to bulk Si for line widths, W > 200 nm; 2) electromagnetic resonance enhancement of the cross section ( to - 100x) for W from 50-200 nm; and 3) highly asymmetric lineshapes and splittings from W < 30 nm. Photoluminescence is observed for the thinnest samples (W < 10 nm) and is as intense as that observed from porous Si with a spectral linewidth ∼ 50 % smaller than that of porous Si.
Continuous silicon carbide fibers (”UF fibers”) with low oxygen content (∼2 wt%) were prepared by dry spinning of high molecular weight polycarbosilane solutions and subsequent pyrolysis of the polymer fibers. Room temperature mechanical properties were similar to those of commercially-available Nicalon™ fibers, as average tensile strengths as high as 3 GPa were obtained for some batches with fiber diameters in the range ∼10–15 μm Furthermore, UF fibers showed significantly better thermomechanical stability compared to Nicalon™, as indicated by lower weight losses, lower specific surface areas, and improved strength retention after heat treatment at temperatures up to 1700°C. UF fibers were also characterized by elemental analysis, X-ray diffraction, and scanning Auger microprobe. Strategies were suggested for achieving further improvements in thermomechanical stability.
A non-contact temperature measurement technique based on diffraction-analysis monitoring of the thermal expansion of materials is discussed. Due to the need for noncontact temperature measurements during semiconductor processing, silicon was chosen for this demonstration. The diffraction method requires a grating of suitable spatial frequency etched on the surface of the silicon wafer. The diffraction angle from the grating depends on the grating period which varies with temperature. Two symmetrically disposed incident beams are used to provide a differential measurement which is relatively independent of sample tilt. A computer system is used to monitor the diffraction order movement, from the order separation a relative temperature change can be calculated in near real-time. Temperature sensitivity for the diffraction technique is inversely dependent on the grating length (number of lines) and independent of the grating width. A sensitivity of 0.75°C is demonstrated for a 3-mm wide grating over a 20-700°C temperature range.
Electrical conductance of single stranded DNA (5′-TTT TTT TTT T/3 Thio MC3-D/-3′) monolayer patterns on Au surface is compared with those of various organic molecular patterns via the conductance microscope (CM) technique that allows one to take nanoscale conductance images utilizing a conducting AFM tip in contact mode AFM. In the experiment, reference molecules and ssDNA are patterned on the same substrate via direct deposition methods such as dip-pen nanolithography and microcontact printing. Then, conductance microscope image is recorded revealing the relative conductivity of ssDNA patterns relative to various reference molecules. 16-mercaptohexadecanoic acid and 2-mercaptobenzimidazole patterns are found conducting better than the ssDNA patterns. This result indicates that the ssDNA with 10T bases is a relatively poor electrical conductor. The capabilities of CM technique are also tested on various nanostructures including the single wall carbon nanotube junction.
We show heteroepitaxial growth of GaAs on Ge/SiGe grown on nanometer-scale grating structures. Conventional lithography techniques were combined with reactive ion and wet-chemical etching to fabricate 1-D patterns of silicon posts. The quality of the GaAs layers was investigated using high-resolution x-ray diffraction (HRXRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), photoluminescence (PL) and etch pit density (EPD) measurements. Our results show significant improvement in the quality of heteroepitaxial layers grown on nano patterned structures compared to those on the unpatterned silicon. The optical quality of the GaAs/Ge/SiGe on nano-scale patterned silicon was comparable to that of single crystal GaAs.
We report highest quality Ge epilayers on nanoscale patterned Si structures. 100% Ge films of 10 μm are deposited using chemical vapor deposition. The quality of Ge layers was examined using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high-resolution x-ray diffraction (HRXRD) measurements. The defect density was evaluated using etch pit density measurements. We have obtained lowest dislocation density (5×105 cm-2) Ge films on the nanopatterned Si structures. The full width half maximum peaks of the reciprocal space maps of Ge epilayers on the nanopatterned Si showed 93 arc sec. We were able to get rid of the crosshatch pattern on the Ge surface grown on the nanopatterned Si. We also showed that there is a significant improvement of the quality of the Ge epilayers in the nanopatterned Si compared to an unpatterned Si. We observed nearly three-order magnitude decrease in the dislocation density in the patterned compared to the unpatterned structures. The Ge epilayer in the patterned Si has a dislocation density of 5×105 cm-2 as compared to 6×108 cm-2 for unpatterned Si.
Cathodoluminescence (CL) of rare earth (RE) ions implanted AlN/GaN superlattice (SL) structures grown by chemical vapor deposition (CVD) technique on GaN/(0001) sapphire substrate was measured at 10 K and 300 K. Implantation of terbium and thulium in SLs was done at 150 keV with a dose of up to 1×1015 cm-2 at 300 K. Samples were given post implantation isochronal thermal treatment at 900 °C in nitrogen ambient. The interface quality between the SL layers before and after implantation as well as after thermal annealing treatment has been investigated by X-ray diffraction (XRD). The characteristic satellite peaks of the SLs were measured for the (0002) reflection in the symmetric Bragg geometry for the reference, RE-implanted, and annealed SLs. Furthermore, the luminescence intensity of a RE3+ ion doped AlN/GaN SL was compared with the one from RE-implanted GaN epilayers. Despite the structural damage of the AlN/GaN structures, an enhancement of the characteristic emission intensities from RE3+ ions in the SLs was observed compared to emission from RE ions in epilayers.