The Impact of the Degree of Aquifer Confinement and Anisotropy on Tidal Pulse Propagation.

Oceanic tidal fluctuations which propagate long distances up coastal rivers can be exploited to constrain hydraulic properties of riverbank aquifers. These estimates, however, may be sensitive to degree of aquifer confinement and aquifer anisotropy. We analyzed the hydraulic properties of a tidally influenced aquifer along the Meghna River in Bangladesh using: (1) slug tests combined with drilling logs and surface resistivity to estimate Transmissivity (T); (2) a pumping test to estimate T and Storativity (S) and thus Aquifer Diffusivity (DPT ); and (3) the observed reduction in the amplitude and velocity of a tidal pulse to calculate D using the Jacob-Ferris analytical solution. Average Hydraulic Conductivity (K) and T estimated with slug tests and borehole lithology were 27.3 m/d and 564 m2 /d, respectively. Values of T and S determined from the pumping test ranged from 400 to 500 m2 /d and 1 to 5 × 10-4 , respectively with DPT ranging from 9 to 40 × 105 m2 /d. In contrast, D estimated from the Jacob-Ferris model ranged from 0.5 to 9 × 104 m2 /d. We hypothesized this error resulted from deviations of the real aquifer conditions from those assumed by the Jacob-Ferris model. Using a 2D numerical model tidal pulses were simulated across a range of conditions and D was calculated with the Jacob-Ferris model. Moderately confined (Ktop /Kaquifer < 0.01) or anisotropic aquifers (Kx /Kz > 10) yield D within a factor of 2 of the actual value. The order of magnitude difference in D between pumping test and Jacob-Ferris model at our site argues for little confinement or anisotropy.

Comparison of entecavir and lamivudine in preventing HBV reactivation in lymphoma patients undergoing chemotherapy: a meta-analysis.

Background Multiple studies have compared the efficacy of entecavir with lamivudine in preventing hepatitis B virus (HBV) reactivation among HBV-carrying lymphoma patients with chemotherapy treatment. However, the results were slightly varied. Aim of the review to combine the findings of independent studies assessing the clinical efficacy of the two drugs using a systematic review and meta-analysis. Methods PubMed, China National Knowledge Infrastructure (CNKI), Chinese Biomedical Literature Database (CBM), Chongqing VIP and WanFang Data were retrieved. Two independent reviewers evaluated the study eligibility and extracted eight studies, with 770 patients in total. The meta-analysis was conducted using RevMan 5.3 and STATA software. Results HBV-carrying lymphoma patients receiving lamivudine during chemotherapy had a statistically significantly higher odds of HBV reactivation compared to those receiving entecavir (OR 5.0, 95 % CI 2.85-8.78, P < 0.001). The odds of hepatitis, HBV-Reactivation caused hepatitis and chemotherapy disruption was statistically significantly elevated in the patient group receiving lamivudine compared to the entecavir group (OR 4.12, 95 % CI 1.70-9.98, P = 0.002; OR 11.44, 95 % CI 2.70-48.52, P < 0.001; OR 6.71, 95 % CI 2.34-19.26, P < 0.001, respectively). Furthermore, the HBV reactivation rate in Ann Arbor stages I - II patient group was statistically significantly lower than the one in Ann Arbor stages III-IV group, with an overall pooled value of 0.37 (95 % CI 0.17-0.82, P = 0.01). Conclusion The metaanalysis result suggested that among HBV-carrying lymphoma patients undergoing chemotherapy, entecavir is more effective than lamivudine in preventing HBV reactivation.