AbstractThis paper focuses on desaturation due to the microbially mediated dissimilatory reduction of nitrogen, or denitrification, for mitigating the potential for earthquake-induced soil ...liquefaction. Denitrification has the potential to mitigate earthquake-induced liquefaction as a two-stage process referred to as microbially induced desaturation and precipitation (MIDP). In MIDP, desaturation provides mitigation in Stage 1, and microbially induced carbonate precipitation (MICP) provides mitigation in Stage 2. Denitrifying bacteria, when stimulated, have the ability to rapidly desaturate a saturated soil by producing nitrogen and carbon dioxide gases. Small amounts of desaturation can significantly increase the cyclic resistance of saturated soil. As this desaturated condition may not last indefinitely, desaturation is relied upon only to provide temporary mitigation. However, in addition to desaturating the soil, denitrifying bacteria can induce MICP by increasing the pH and carbonate alkalinity of the pore fluid. Interparticle cementation, void filling, and particle roughening induced by MICP improve the cyclic resistance and dilatant behavior of granular soil, thereby providing long-term mitigation of liquefaction. This paper describes the use of desaturation via denitrification for short-term mitigation of earthquake-induced liquefaction. The use of MICP via denitrification as a long-term solution is presented in a companion paper.
AbstractThis paper focuses on the potential for microbially induced carbonate precipitation (MICP) via dissimilatory reduction of nitrogen, or denitrification, to mitigate the potential for ...earthquake-induced soil liquefaction. Denitrification has the potential to provide mitigation of earthquake-induced soil liquefaction as a two-stage process referred to by the authors as microbially induced desaturation and precipitation (MIDP). In MIDP, desaturation provides mitigation in Stage 1 and MICP provides mitigation in Stage 2. Denitrifying bacteria, when stimulated, have the ability to rapidly desaturate a saturated soil via gas production, thereby significantly increasing the cyclic resistance of the soil. However, because this desaturated condition may not last indefinitely, desaturation is only relied upon to provide temporary mitigation in MIDP. In Stage 2 of MIDP, interparticle cementation, void filling, and particle roughening as a result of MICP significantly improve the strength, stiffness, dilatant behavior, and cyclic strength of the soil, thereby providing long-term liquefaction mitigation (i.e., after denitrification has ceased). This paper describes the use of MICP via denitrification for the long-term mitigation of earthquake-induced liquefaction. Desaturation via denitrification for the short-term mitigation of liquefaction potential is presented in a companion paper.
AbstractA biogeochemical model describing the rate at which calcium carbonate (CaCO3) is precipitated from the pore water and biogas (carbon dioxide and nitrogen gas) is generated by dissimilatory ...reduction of nitrate (denitrification) through microbially induced desaturation and precipitation (MIDP) has been developed. Both CaCO3 precipitation and desaturation via biogas formation can improve the static and cyclic mechanical properties of granular soil. CaCO3 precipitation can improve the static and cyclic stiffness, shear strength, and volume change characteristics of granular soil. Desaturation via biogenic gas generation suppresses excess pore pressure development and thereby improves the cyclic shear resistance of granular soil. MIDP represents the combined effect of these two mechanisms. Effective implementation of MIDP for ground improvement demands quantitative understanding of the rate at which both mechanisms occur. The biogeochemical model developed herein is an upgrade of the model presented in earlier research; it includes additional features, such as inhibition terms, an expanded number of organic substrates, and a greater number of chemical constituents. It predicts the rate of CaCO3 precipitation and gas production by integrating stoichiometry, thermodynamics, microbial growth kinetics, and chemical reaction kinetics for a continuously stirred batch reactor. The model was calibrated using results from laboratory test columns. Sensitivity analyses conducted using the calibrated model identified a molar ratio for acetate:calcium:nitrate of 0.9∶1.0∶1.0 as the preferred ratio for maximizing CaCO3 precipitation and gas generation while avoiding excess residuals in the modeled batch reactor system.
Condyloma and Anal Dysplasia Haviland, Sarah M; O'Donnell, Mary T
The Surgical clinics of North America
104, Številka:
3
Journal Article
Recenzirano
Anal intraepithelial neoplasia (AIN) are precancerous lesions and are sequela of human papilloma virus (HPV) infection. AIN is classified as low-grade squamous intraepithelial lesion or high-grade ...squamous intraepithelial lesion. Screening with anal cytology and anoscopy should be considered for high-risk populations. Diagnosis is made through high resolution anaoscopy and biopsy. Options for treatment include ablation and several topical therapies; however, recurrence rates are high for all treatment options, and an ongoing surveillance is necessary to prevent progression to anal squamous cell carcinoma. HPV vaccination is recommended to prevent disease.
Women remain underrepresented in cardiothoracic surgery (CTS). In 2005, Women in Thoracic Surgery (WTS) began offering scholarships to promote engagement of women in CTS careers. This study explores ...the effect of WTS scholarships on CTS career milestones.
We assessed career development using the number of awardees matching into CTS residency/fellowship, American Board of Thoracic Surgery (ABTS) certification, and academic CTS appointment. Scholarship awardee data were obtained from our WTS database. Comparison data were gathered from the National Residency Match Program and ABTS. Details of the current roles of ABTS-certified women were determined from public resources. Qualitative results were gathered from post-scholarship surveys.
A total of 106 WTS scholarships have been awarded to 38 medical students (36%), 41 general surgery residents (39%), and 27 CTS residents/fellows (25%). Among medical students, 26% of awardees entered integrated CTS residency (vs <0.1% for medical students, P < .001), and 37% entered general surgery residency (vs 4.8% for medical students, P < .001). Of general surgery awardees, 59% entered CTS fellowships (vs 7.7% for general surgery residents, P < .001), and of CTS resident/fellow awardees, 100% earned ABTS certification (vs 73% ABTS pass rate, P = .01). Of ABTS-certified awardees, 44% are practicing cardiothoracic surgeons at US academic training institutions (vs 33% of non-awardee ABTS-certified women, P = .419). All awardees reported that their scholarship was valuable in their development.
Receipt of a WTS scholarship is associated with successful pursuit of CTS career milestones at significantly higher rates than contemporaries. These scholarships foster a supportive community for women trainees in CTS.
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Constipation encompasses symptoms of decreased colonic motility or difficulty with the defecation process. As a broad definition, this can be inclusive of functional constipation (FC) or colonic ...inertia, obstructed defecation (OD), and irritable bowel syndrome-constipation type (IBS-CS). After excluding IBS-C, FC and OD diagnosis and management require a multidisciplinary approach often involving nutritionists, pelvic floor therapists, urogynecologists, and colon and rectal surgeons. Differentiating the presence or absence of each can direct therapy and prognosticate chances for improvement in this often complex combination of disorders.
A key limitation for achieving deep imaging in biological structures lies in photon absorption and scattering leading to attenuation of fluorescence. In particular, neurotransmitter imaging is ...challenging in the biologically relevant context of the intact brain for which photons must traverse the cranium, skin, and bone. Thus, fluorescence imaging is limited to the surface cortical layers of the brain, only achievable with craniotomy. Herein, this study describes optimal excitation and emission wavelengths for through‐cranium imaging, and demonstrates that near‐infrared emissive nanosensors can be photoexcited using a two‐photon 1560 nm excitation source. Dopamine‐sensitive nanosensors can undergo two‐photon excitation, and provide chirality‐dependent responses selective for dopamine with fluorescent turn‐on responses varying between 20% and 350%. The two‐photon absorption cross‐section and quantum yield of dopamine nanosensors are further calculated, and a two‐photon power law relationship for the nanosensor excitation process is confirmed. Finally, the improved image quality of the nanosensors embedded 2‐mm‐deep into a brain‐mimetic tissue phantom is shown, whereby one‐photon excitation yields 42% scattering, in contrast to 4% scattering when the same object is imaged under two‐photon excitation. The approach overcomes traditional limitations in deep‐tissue fluorescence microscopy, and can enable neurotransmitter imaging in the biologically relevant milieu of the intact and living brain.
The two‐photon excitation of single‐walled carbon nanotube nanosensors produces a near‐infrared fluorescent signal in response to the neurotransmitter dopamine. Both the excitation (1560 nm) and emission (900–1400 nm) wavelengths fall within a local transmittance maximum for brain tissue, scalp, and cranial bone, enabling dopamine imaging deep into highly scattering media.
Fragile X syndrome is one of the most common forms of inherited mental retardation. In most cases the disease is caused by the methylation-induced transcriptional silencing of the fragile X mental ...retardation 1 (FMR1) gene that occurs as a result of the expansion of a CGG repeat in the gene's 5'UTR and leads to the loss of protein product fragile X mental retardation protein (FMRP). FMRP is an RNA binding protein that associates with translating polyribosomes as part of a large messenger ribonucleoprotein (mRNP) and modulates the translation of its RNA ligands. Pathological studies from the brains of patients and from Fmr1 knockout mice show abnormal dendritic spines implicating FMRP in synapse formation and function. Evidence from both in vitro and in vivo neuronal studies indicates that FMRP is located at the synapse and the loss of FMRP alters synaptic plasticity. As synaptic plasticity has been implicated in learning and memory, analysis of synapse abnormalities in patients and Fmr1 knockout mice should prove useful in studying the pathogenesis of fragile X syndrome and understanding learning and cognition in general. If an appreciable portion of the total variance (in IQ) is due to sex linked genes, it is of more importance that a boy should have a clever mother than a clever father. Hogben 1932 (quoted in Lehrke 1974)
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Non-Hodgkin lymphoma (NHL) affects over 400,000 people in the United States; its incidence increases with age. Treatment options are numerous and expanding, yet efficacy is often limited by toxicity, ...particularly in the elderly. Nearly 70% patients eventually die of the disease. Many patients explore less toxic alternative therapeutics proposed to boost anti-tumor immunity, despite a paucity of rigorous scientific data. Here we evaluate the lymphomacidal and immunomodulatory activities of a protein fraction isolated from fermented wheat germ. Fermented wheat germ extract was produced by fermenting wheat germ with Saccharomyces cerevisiae. A protein fraction was tested for lymphomacidal activity in vitro using NHL cell lines and in vivo using mouse xenografts. Mechanisms of action were explored in vitro by evaluating apoptosis and cell cycle and in vivo by immunophenotyping and measurement of NK cell activity. Potent lymphomacidal activity was observed in a panel of NHL cell lines and mice bearing NHL xenografts. This activity was not dependent on wheat germ agglutinin or benzoquinones. Fermented wheat germ proteins induced apoptosis in NHL cells, and augmented immune effector mechanisms, as measured by NK cell killing activity, degranulation and production of IFNγ. Fermented wheat germ extract can be easily produced and is efficacious in a human lymphoma xenograft model. The protein fraction is quantifiable and more potent, shows direct pro-apoptotic properties, and enhances immune-mediated tumor eradication. The results presented herein support the novel concept that proteins in fermented wheat germ have direct pro-apoptotic activity on lymphoma cells and augment host immune effector mechanisms.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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