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The Lower Silurian Longmaxi shale is the most important marine shale gas play in South China. Several hundred wells have been drilled to date, of which more than 150 wells have obtained high initial production (IP). Outside of the Sichuan Basin, however, wells drilled in the Lower Silurian Longmaxi shale do not reach flow rates that are commercial. Developing an understanding of the key factors controlling the IPs of Longmaxi shale is important in screening shale-resource plays. In this study, the TOC, thermal maturity, porosity, and gas saturation data obtained from Longmaxi shale of southeastern Chongqing area outside Sichuan Basin have been compared with that of Sichuan Basin. The results of this study show that the shales encountered display similar properties including TOC (>2%), thermal maturity (2.5–3.5% EqRo), and total porosity (3–6%). A good correlation between IPs and pressure coefficient suggest that the free gas content of gas shale controls on IPs. Porosity and gas saturation of gas shale are the main factors to control its free gas volume. The gas saturations in Longmaxi shale from high initial production wells in Sichuan Basin mainly range between 50 and 90%, however, that of shale in the southeastern Chongqing area are decreased to 10–30%. This is the directly reason for low IPs of wells. The contrasting gas saturation of Longmaxi shale between Sichuan Basin and the adjacent fold-thrust belts are interpreted to reflect, in part, differences in sealed condition of fluid system. Intensive tectonic movements caused the exhumation, faulting and fracturing, that reduced or destroyed the sealed ability of shale fluid system, which are the major factors for enhancing water saturation, decreasing fluid pressure and IPs. Finally, the study proposes several most favorable zones for Longmaxi shale gas exploration and development.

Zhou J, Bates BE, Kurichi JE, Kwong PL, Xie D, Stineman MG. Factors influencing receipt of outpatient rehabilitation services among veterans following lower extremity amputation. Objective To determine patient-, treatment-, and facility-level characteristics associated with receiving outpatient rehabilitation services after lower extremity amputation within the Veterans Affairs (VA) system. Design Observational study. Setting All Veterans Affairs Medical Centers (VAMCs). Participants Veterans (N=4165) with lower extremity amputation discharged from VAMCs between October 1, 2002, and September 20, 2004. Interventions Not applicable. Main Outcome Measures Receipt of outpatient rehabilitation services up to 1 year postdischarge. A Cox proportional hazards model was used to determine the adjusted hazard ratio and 95% confidence interval of veterans to receive outpatient services. Results Sixty-five percent of veterans with lower extremity amputation received outpatient services. Older veterans, patients admitted for surgical amputation from extended care rather than transferred from another hospital, and those with transfemoral and/or bilateral rather than unilateral transtibial amputations were less likely to receive outpatient services. Those with serious comorbidities and those who had procedures for acute central nervous system disorders, active cardiac pathology, serious nutritional compromise, and severe renal disease during the surgical hospitalization less often initiated outpatient care. Patients who received inpatient consultative rehabilitation compared with inpatient specialized rehabilitation, and who were treated in the Northeast compared with the Southeast less often initiated outpatient care. Finally, those discharged to home or other locations rather than extended care had an initial increased likelihood of receiving outpatient service, but by 180 days postdischarge those discharged to extended care were more likely to initiate outpatient services. Conclusions Both clinical characteristics and types of rehabilitation services received appear to influence the receipt of outpatient rehabilitation services. Geographic location also affected the receipt of outpatient rehabilitation, suggesting that care patterns are not standardized across the nation.

The basic helix–loop–helix (bHLH) transcription factor Math5 (Atoh7) is required for retinal ganglion cell (RGC) and optic nerve development. Using Math5-lacZ knockout mice, we have identified an additional expression domain for Math5 outside the eye, in functionally connected structures of the central auditory system. In the adult hindbrain, the cytoplasmic Math5-lacZ reporter is expressed within the ventral cochlear nucleus (VCN), in a subpopulation of neurons that project to medial nucleus of the trapezoid body (MNTB), lateral superior olive (LSO), and lateral lemniscus (LL). These cells were identified as globular and small spherical bushy cells based on their morphology, abundance, distribution within the cochlear nucleus (CN), co-expression of Kv1.1, Kv3.1b and Kcnq4 potassium channels, and projection patterns within the auditory brainstem. Math5-lacZ is also expressed by cochlear root neurons in the auditory nerve. During embryonic development, Math5-lacZ was detected in precursor cells emerging from the caudal rhombic lip from embryonic day (E)12 onwards, consistent with the time course of CN neurogenesis. These cells co-express MafB and are post-mitotic. Math5 expression in the CN was verified by mRNA in situ hybridization, and the identity of positive neurons was confirmed morphologically using a Math5-Cre BAC transgene with an alkaline phosphatase reporter. The hindbrains of Math5 mutants appear grossly normal, with the exception of the CN. Although overall CN dimensions are unchanged, the lacZ-positive cells are significantly smaller in Math5 −/− mice compared to Math5 +/− mice, suggesting these neurons may function abnormally. The auditory brainstem response (ABR) of Math5 mutants was evaluated in a BALB/cJ congenic background. ABR thresholds of Math5 −/− mice were similar to those of wild-type and heterozygous mice, but the interpeak latencies for Peaks II–IV were significantly altered. These temporal changes are consistent with a higher-level auditory processing disorder involving the CN, potentially affecting the integration of binaural sensory information.

Recent findings show that the vanilloid receptor subtype 1 (TRPV1) is expressed by cochlear outer hair cells and spiral ganglion cells, and that its expression is up-regulated in ganglion cells after aminoglycoside treatment. This study tested the hypothesis that agents that act on TRPV1 receptors affect the spectrum of ensemble background activity (EBA). Consecutive intracochlear perfusions of the TRPV1 agonist, capsaicin (CAP 0.1, 1, and 10 parts per million), as well as its antagonist capsazepine (CZP), were used to test effects of TRPV1 activation on EBA recorded from the cochlear base. Perfusion with CAP alone produced a dose-dependent increase of the 900-Hz peak ratio (power normalized re the overall spectrum) of the EBA. The CAP effect was attenuated during concurrent perfusion with CZP. These findings are consistent with the hypothesis that TRPV1 activation increases background activity of spiral ganglion cells and support a role of TRPV1 in gating spontaneous and evoked auditory nerve excitability.

Interactions between somatosensory and auditory systems occur at peripheral levels in the central nervous system. The cochlear nucleus (CN) receives innervation from trigeminal sensory structures: the ophthalmic division of the trigeminal ganglion and the caudal and interpolar regions of the spinal trigeminal nucleus (Sp5I and Sp5C). These projections terminate primarily in the granule cell domain, but also in magnocellular regions of the ventral and dorsal CN. Additionally, new evidence is presented demonstrating that cells in the lateral paragiganticular regions of the reticular formation (RF) also project to the CN. Not unlike the responses obtained from electrically stimulating the trigeminal system, stimulating RF regions can also result in excitation/inhibition of dorsal CN neurons. The origins and central connections of these projection neurons are associated with systems controlling vocalization and respiration. Electrical stimulation of trigeminal and RF projection neurons can suppress acoustically driven activity of not only CN neurons, but also neurons in the inferior colliculus. Together with the anatomical observations, these physiological observations suggest that one function of somatosensory input to the auditory system is to suppress responses to "expected" body-generated sounds such as vocalization or respiration. This would serve to enhance responses to "unexpected" externally-generated sounds, such as the vocalizations of other animals.

The deformation and uplifting history of the Qinghai–Tibet Plateau is a controversial issue, and so far there has been insufficient evidence for interpretation. Investigations of the Cenozoic deformation in the northeastern edge of this plateau may provide some relevant information. In this paper, the Cenozoic deformation history of the Qaidam Basin has been studied based on results from the balanced cross-section restoration of six geological sections. They indicate that: (1) the Qaidam Basin has been undergoing continuous shortening since the beginning of Cenozoic with two relatively fast shortening phases, the first during 42.8–40.5 Ma and the second during 2.8 Ma–present; (2) the shortening rate of the Qaidam Basin reached its maximum value since 2.8 Ma, and approximately 32% of the average total Cenozoic shortening took place in this period; and (3) the shortening of all sections reached approximately 50% of their respective total shortening by Miocene. The Cenozoic deformation history of the Qaidam Basin shows good synchroneity with uplifting history of the Qinghai–Tibet Plateau. It is therefore proposed that the deformation and uplifting in the south and north edges of the Qinghai–Tibet Plateau was almost synchronous, with the Altyn Tagh Fault formed at the beginning of India–Asia collision. Accordingly, it is postulated that since the India–Asia collision at the beginning of Cenozoic, the Indian Plate moved northward continuously with two relatively fast phases, the first during 42.8–40.5 Ma and the second during 2.8 Ma–present. Approximately 50% of the total Cenozoic northward displacement of the Indian Plate, of the total amount of crustal shortening and uplifting of the Qinghai–Tibet Plateau, and of the total Cenozoic strike slip displacement of the Altyn Tagh Fault were probably reached by the early Miocene. Moreover, another 30–40% might have taken place during 2.8 Ma–present. The periods during 42.8–40.5 Ma and during 2.8 Ma–present may also be the two fast phases for crustal shortening and uplifting of the Qinghai–Tibet Plateau and strike slip displacement of the Altyn Tagh Fault.

A separation-based biosensor that couples microdialysis directly to capillary electrophoresis with electrochemical detection (CEEC) is described. The system employs a 60 nl injection valve and a gap junction interface. For successful electrochemical detection, it is necessary to apply the separation voltage at the gap interface. This is in contrast to previously reported optically based systems in which it was possible to place the high voltage at the detection end. To protect the experimental animal from the high voltage employed for the separation, a cellulose acetate-based decoupler was placed between the injection valve and the injection interface. The effects of interface gap distance, transfer buffer flow rate and capillary i.d. on separation efficiency and peak height were investigated. In particular, it was found that electrokinetic injection of positively charged analytes into the CE was affected by the magnitude of the second field set up in the transfer capillary. The use of a 25 μm diameter capillary for the transfer line and a 75 μm capillary for the CE separation gave the best detector response and highest separation efficiency. The potential of this system for bioanalytical studies was demonstrated by monitoring transdermal delivery of nicotine following administration of a nicotine patch. Cutaneous concentrations of nicotine were monitored over a 24 h period with a resolution of 10 min.

Thiols and disulfides are separated and detected by capillary electrophoresis-electrochemical detection using a mixed-valence ruthenium cyanide-modified microelectrode. A carbon fiber array microelectrode was employed to maximize the signal-to-noise ratio. Detection limits for glutathione disulfide, cystine and homocystine were 2.5, 1.3 and 1.1 fmol, respectively. The response for cystine was linear over two orders of magnitude with a correlation coefficient of 0.992. The long-term stability and overall reproducibility of the electrode were investigated and found to be highly dependent on the cation concentration in the electrophoretic buffer. The selectivity of this technique for disulfides was demonstrated by the detection of cystine in the urine of a patient with kidney stones.

Thionine-containing chemically modified electrode ( cme ) was constructed with glassy carbon substrate by potential sweep oxidation, electrodeposition and adsorption procedures, and electrocatalytic reduction of hemoglobin was carried out and characterized at the cme under batch and flow conditions. Comparison of the catalytic response toward hemoglobin obtained at the cme was made mainly in terms of the potential dependence, the detectability and long-term stability. When used in flow injection analysis (FIA) experiments with the detector monitored at a constant potential applied at −0.35 vs sce , detection limit of 0.15–1.5 pmol level of hemoglobin injected was achieved at the cme , with linear response range over 2 orders of magnitude. All the cme s retained more than 70% of their initial hemoglobin response level over 8 h of continuous service in the flow-through system.

A new liquid chromatography electrochemical (LCEC) scheme for glucose sensing has been developed on the basis of a Prussian Blue chemically modified electrode (CME) of novel construction and characterized in terms of various experimental parameters by the flow injection analysis (FIA) technique. Unique hydrodynamic voltammograms were obtained for the first time at the CME in the flow-through amperometric detection of glucose, and subsequently both anodic and cathodic peaks could be expected on monitoring the operating potential in the modest positive or negative region. The unique pH dependence on the CME response towards glucose makes it perfectly compatible with conventional reversed phase liquid chromatography systems. On the basis of these features, practical application in glucose LCEC detection has been effectively performed; a linear response range over three orders of magnitude and a detection limit of subpicomole level were readily obtained. The capability of the established LCEC mode in the direct sensing of urinary glucose has been demonstrated.

A copper-based chemically-modified electrode has been constructed and characterized by various experimental parameters in flow-through amperometric detection of carboxylic acids and phenolic acids. Novel hydrodynamic voltamperograms were first obtained in flow-through amperometric detection with the Cu-based CME and subsequently negative and positive peaks were observed in a single chromatogram. This unique and flexible potential dependence could be of great benefit in chromatographic speciation and quantification. These observations suggest that the detector response was governed by the complexation reaction of copper ions with the solutes.

Steady-state voltammetric and flow-through thin-layer amperometric experiments were done to investigate the influence of various preliminary experimental conditions on the selectivity of a Nafion-coated electrode in the flow-through determination of cationic drugs (promethiazine was selected as a model compound). From the results guidelines were formulated to obtain optimum selectivity for cationic drugs with a Nafion-coated electrode in flow-through analysis.