Analytical solutions of contaminant transport in homogeneous and isotropic aquifer in three-dimensional groundwater flow.

Modeling three-dimensional contaminant transport released from arbitrary shape source geometries is useful in hydrological and environmental sciences. This article produces several analytical solutions for three-dimensional contaminant transport in a homogeneous and isotropic aquifer by using Green's function with the groundwater flow which is assumed to be in three directions. The solutions are obtained for both finite depth aquifer and semi-infinite depth aquifer. Various types of sources are discussed: point, line, plane, or cuboid sources. The continuous and instantaneous sources are also investigated. A MATLAB coding is developed to calculate the numerical integrals which occur at the solutions. Some solutions are verified with the solutions obtained in the literature. This study confirms the effect of groundwater velocities in all directions on the degree and the directions of contaminant spreading. Additionally, the results highlight the significant effect of the geometrical shape of the contaminant sources on contaminant concentrations for instantaneous and continuous sources. In particular, the cuboid source and the horizontal rectangular source provide the highest concentrations. The analytical solutions developed in this article can be applied for a wide range of contaminant transport.

Effect of delayed cord clamping on stem cell transfusion and hematological parameters in preterm infants with placental insufficiency: a pilot randomized trial.

The feasibility of delayed cord clamping (DCC) in preterm infants with placental insufficiency (PI) is questionable. We aimed to study the effect of DCC on stem cell transfusion, hematological parameters, and clinical outcomes in preterm infants born to mothers with PI. Preterm infants, < 34 weeks' gestation, born to mothers with PI were randomized based on the timing of umbilical cord clamping into delayed clamping for 60 s (DCC group) or immediate cord clamping (ICC group) groups at time of birth. CD34 percentage as a marker of stem cell transfusion, early and late-onset anemia, hypothermia, hypotension, polycythemia, hyperbilirubinemia, duration of oxygen therapy, bronchopulmonary dysplasia, intra-ventricular hemorrhage, necrotizing enterocolitis, sepsis, mortality, and length of hospital stay were compared between studied groups. We found that peripheral blood CD34 percentage was significantly higher in DCC compared with that in the ICC group (median (IQR) of 0.5 (0.40-0.7) versus 0.35 (0.20-0.5), p = 0.004). Infants in the DCC group had significantly lower episodes of anemia of prematurity at 2 months, red blood cell transfusion, and shorter duration of oxygen therapy compared with those in the ICC group.Conclusion: In conclusion, DCC compared with ICC increased stem cell transfusion and decreased early- and late-onset anemia in preterm infants with placental insufficiency.Trial registration: NCT03731546 www.clinicaltrials.gov What is Known: • Delayed cord clamping has been recommended by the American Academy of Pediatrics as a standard of care practice during delivery of preterm infants. • The feasibility of DCC in preterm infants with placental insufficiency (PI) is uncertain. What is New: • This randomized controlled trial demonstrated that DCC in the delivery room care of preterm infants born to mothers with placental insufficiency increased stem cell transfusion and decreased early- and late-onset anemia.

Incidence, Risk Factors and Treatment Outcomes of Intraocular Hypertension and/or Glaucoma Post-Penetrating Keratoplasty: A 5-Year Lebanese Retrospective Descriptive Study.

PURPOSE: Glaucoma is one of the most common complications post-penetrating keratoplasty (PK). In this study, we report the Incidence, risk factors and treatment outcomes of intraocular hypertension (IOH) or/and glaucoma post-penetrating keratoplasty (PKG). METHODS: A 5-year descriptive retrospective study, Lebanese patients who underwent PK at Beirut Eye & ENT Specialist Hospital, between 2012 and 2017, were included. Patients with history of glaucoma were excluded. IOH/PKG cases that necessitate treatment were identified and analyzed for the incidence, risk factors and treatment outcomes. RESULTS: A total of 189 eyes of 159 patients were included, with male/female ratio 1.6 and the mean age 47.2±21.3 years. Bullous keratopathy (BK) presented with a high mean age: 70.3 years while ectasia patients were the youngest: 36.5 years. 34.9% of eyes developed high IOP within a mean of 25 months of follow-up distributed between sub-groups of patient with corneal ectasia (22.5%), redo-PK (51.2%), bullous keratopathy (BK) (50%), keratitis (24.9%), and others (dystrophy, trauma …) (21.4%). High IOP developed in 67.4% of the diabetic patients. Visual acuity was less likely to improve in cases developing elevated IOP while postoperative complications were significantly high. In those refractory to medical treatment, trabeculectomy as a glaucoma surgery was effective in lowering the IOP. Combining procedures with PK was not a risk factor for glaucoma. Interrupted sutures and higher number of suturing were associated with increased IOP levels. CONCLUSION: IOH developed in one out of three patients who underwent penetrating keratoplasty. DM, bullous keratopathy, infectious keratitis and redo-PK were highly associated with PKG, whereas high IOP was less likely to develop in cases with keratoconus. Glaucoma is considered a poor prognostic factor in patients post-PK.

Solute transport modelling to manage groundwater pollution from surface water resources.

This article provides an analytical solute transport model to investigate the potential of groundwater contamination by polluted surface water in a two dimensional domain. The clogging of streambed which makes the aquifer partially penetrated by the stream, is considered in the model. The impacts of pumping process, hydraulic conductivity and clogging layer on the quality of water produced from nearby drinking water wells are evaluated. It is found that results are consistent with numerical simulation conducted by MODFLOW software. Moreover, the model is applied using data of contamination occurrence in Malaysia, where high contaminants concentrations are found close to streams. Results show that the pumping activities (rate and time period) are crucial factors when evaluating the risk of groundwater contamination from surface water. Additionally, this study illustrates that the increase in either hydraulic conductivity or leakance coefficient parameters due to the clogging layer will enlarge the area of contamination. The model is able to determine the suitable pumping rate and location of the well so that the contamination plume never reaches the extraction well, which is useful in constructing riverbank filtration sites.

Analytical Modeling of Well Design in Riverbank Filtration Systems.

Analytical studies for well design adjacent to river banks are the most significant practical task in cases involving the efficiency of riverbank filtration systems. In times when high pollution of river water is joined with increasing water demand, it is necessary to design pumping wells near the river that provide acceptable amounts of river water with minimum contaminant concentrations. This will guarantee the quality and safety of drinking water supplies. This article develops an analytical solution based on the Green's function approach to solve an inverse problem: based on the required level of contaminant concentration and planned pumping time period, the shortest distance to the riverbank that has the maximum percentage of river water is determined. This model is developed in a confined and homogenous aquifer that is partially penetrated by the stream due to the existence of clogging layers. Initially, the analytical results obtained at different pumping times, rates and with different values of initial concentration are checked numerically using the MODFLOW software. Generally, the distance results obtained from the proposed model are acceptable. Then, the model is validated by data related to two pumping wells located at the first riverbank filtration pilot project conducted in Malaysia.

Hypercalcemia in a bodybuilder with cosmetic silicone injections.

Granulomatous hypercalcemia due to silicone injections is a rare disease with scarce literature. We present a case of a 35-year-old Caucasian male bodybuilder with multiple silicone injections in his upper extremities who developed hypercalcemia and urinary symptoms. He necessitated two sessions of dialysis. A biopsy of the upper arm showed granulomatous tissue. Corticosteroids were administered to relieve symptoms and reverse laboratory abnormalities. Silicone-induced hypercalcemia should be on high alert because of the increasing trend of body contour enhancements with injections, implants and fillers.

Waste bones ash as an alternative source of P for struvite precipitation.

Struvite precipitation has been widely applied for the removal of ammonium-nitrogen (NH4-N) from wastewater. Due to the high cost of phosphorus (P) reagents, the current research trend was directed to find alternative sources of P, in order to maintain a sustainable NH4-N removal process. The current study investigated waste bones ashes as alternative sources of P. Different types of bones' ashes were characterized, in which the ash produced from waste fish bones was the highest in P content (17%wt.). The optimization of the factors affecting P extraction from ash by acidic leaching showed that applying 2M H2SO4 and 1.25 kg H2SO4/kg ash achieved the highest P recovery (95%). Thereafter, the recovered P was successfully used in struvite precipitation, which achieved more than 90% NH4-N removal and high purity struvite.

Association of CYP3A4/5 genotypes and expression with the survival of patients with neuroblastoma.

Neuroblastoma (NB) is a rare pediatric disease in Lebanon for which poor prognosis remains a major challenge. Genetic polymorphism of genes coding for drug­metabolizing enzymes may influence the response of a patient to chemotherapy. This study investigates a possible association between CYP3A4/5 polymorphism and expression levels and survival in NB patients. All patients with stage III and IV NB diagnosed between 1993 and 2012 in three major hospitals in Beirut were included (n=27). Demographic information and survival time were obtained from medical records. CYP3A4 and CYP3A5 genotypes and expression levels were determined in archival tumors by polymerase chain reaction (PCR) and restriction fragment length polymorphism and quantitative PCR, respectively. Additionally, MYCN amplification was assessed. A Cox proportional hazards model was used to evaluate potential associations, adjusting for MYCN amplification. A statistically significant increase in the risk of mortality was observed in patients with MYCN amplification [hazard ratio (HR) 4.11, 95% confidence interval (CI) 1.14­14.80]. Patients with CYP3A5 expression levels above the median had a lower risk of mortality (HR 0.61, 95% CI 0.21­1.74) and patients with CYP3A4 expression levels above the median had a higher risk of mortality (HR 2.00, 95% CI 0.67­5.90). CYP3A5*3/*3 homozygote mutants had a 4.3­fold increase in the risk of mortality compared with that of homozygote wild­type or heterozygote mutants (HR 4.30, 95% CI 0.56­33.30). Carriers of the CYP3A4*1B mutant allele had a 52% lower risk of mortality compared with that of non­carriers (HR 0.48, 95% CI 0.06­3.76). Although the results of the present study did not achieve statistical significance, associations were observed, which indicates that CYP3A4 and CYP3A5 may modulate the clinical outcome of NB. Further studies with larger sample sizes are required to characterize the effects of the polymorphism and expression levels of CYP3A4/5 on the survival of patients with NB.