416 research outputs found
Nonlinear photoluminescence spectra from a quantum dot-cavity system: Direct evidence of pump-induced stimulated emission and anharmonic cavity-QED
We investigate the power-dependent photoluminescence spectra from a strongly
coupled quantum dot-cavity system using a quantum master equation technique
that accounts for incoherent pumping, pure dephasing, and fermion or boson
statistics. Analytical spectra at the one-photon correlation level and the
numerically exact multi-photon spectra for fermions are presented. We compare
to recent experiments on a quantum dot-micropiller cavity system and show that
an excellent fit to the data can be obtained by varying only the incoherent
pump rates in direct correspondence with the experiments. Our theory and
experiments together show a clear and systematic way of studying
stimulated-emission induced broadening and anharmonic cavity-QED.Comment: We have reworked our previous arXiv paper and submitted this latest
version for peer revie
Measurement of Liquid Core Length of a Coaxial Two-fluid Spray
Shadowgraphs, tube-source X-ray radiographs, and synchrotron X-ray radiographs from a coaxial two-fluid spray are analyzed to measure the liquid core length of the spray. Two flow conditions: Rel = 1,100, Reg = 21,300, We = 40, and Rel = 1,100, Reg = 46,700, We = 196 are investigated. The standard deviation of the fluctuating intensity values are calculated and analyzed to estimate the liquid core length. Additionally, the largest connected domain is used to find an instantaneous breakup position of the spray. The results show that the high standard deviation region is related to the ligament development region, and the instantaneous position identifies ligament formation in the spray
Pennsylvania Folklife Vol. 32, No. 1
• European Antecedents of Seventeenth and Eighteenth Century Germanic and Scots-Irish Architecture in America • Medicine, Music and Money Munyon • Ebbes Neieshttps://digitalcommons.ursinus.edu/pafolklifemag/1097/thumbnail.jp
Urinary, Circulating, and Tissue Biomonitoring Studies Indicate Widespread Exposure to Bisphenol A
Bisphenol A (BPA) is one of the highest-volume chemicals produced worldwide, and human exposure to BPA is thought to be ubiquitous. Thus, there are concerns that the amount of BPA to which humans are exposed may cause adverse health effects. We examined many possibilities for why biomonitoring and toxicokinetic studies could come to seemingly conflicting conclusions. More than 80 published human biomonitoring studies that measured BPA concentrations in human tissues, urine, blood, and other fluids, along with two toxicokinetic studies of human BPA metabolism were examined. Unconjugated BPA was routinely detected in blood (in the nanograms per milliliter range), and conjugated BPA was routinely detected in the vast majority of urine samples (also in the nanograms per milliliter range). In stark contrast, toxicokinetic studies proposed that humans are not internally exposed to BPA. Available data from biomonitoring studies clearly indicate that the general population is exposed to BPA and is at risk from internal exposure to unconjugated BPA. The two toxicokinetic studies that suggested human BPA exposure is negligible have significant deficiencies, are directly contradicted by hypothesis-driven studies, and are therefore not reliable for risk assessment purposes.Bisfenol A (BPA) é um dos produtos químicos mais produzido em todo o mundo, e a exposição humana a ele é considerada onipresente. Assim, há preocupações de que a quantidade de BPA para o qual os seres humanos estão expostos podem causar efeitos adversos à saúde. Nós examinamos muitas possibilidades sobre o porquê estudos de biomonitorização e toxicocinética podem chegar a conclusões aparentemente conflitantes. Mais de 80 estudos publicados de biomonitorização humana que mediram a concentração de BPA em tecidos humanos, urina, sangue e outros fluidos, juntamente com dois estudos de toxicocinética do metabolismo humano BPA foram examinados. BPA não conjugado foi detectado no sangue (nonanogramas por mililitro gama), e BPA conjugado foi detectado na grande maioria das amostras de urina. Em contraste, estudos de toxico-cinética propuseram que os seres humanos não são internamente expostos ao BPA. Dados disponíveis de estudos de biomonitorização indicam que a população em geral está exposta ao BPA e em risco de exposição interna ao BPA não conjugado. Os dois estudos de toxicocinética, que sugeriram a exposição humana ao BPA é insignificante, têm deficiências significativas e estão diretamente refutados por outros estudos e, portanto não são confiáveis para fins de avaliação de risco
Seventy-Five Years (1940-2015) of Lehigh University\u27s Chemistry Department
The 75-years 1940 to 2015 have been exciting ones for the Department of Chemistry; new buildings, new programs, energetic young faculty, enhanced research image, and a far broader coverage of Chemistry than our ancestors ever presumed. Five chairs guided the department through its first 75-years but it took 11 chairs (with two of them serving twice) to manage the second 75-years. As one of the Lehigh founding departments in 1865 our first 75-years have already been covered. The reader is directed to a history written by Robert D. Billinger, A History of the Department of Chemistry and Chemical Engineering of Lehigh University, Bethlehem, Pennsylvania (1866-1941) which is available in original in the Lehigh Archives and as an on-line document. This sesquicentennial volume is also available in hardcopy with original illustrations in the archives or on-line
Pheochromocytoma presenting with arterial and intracardiac thrombus in a 47-year-old woman: a case report
<p>Abstract</p> <p>Introduction</p> <p>Pheochromocytoma is a rare cause of hypertension but it could have severe consequences if not recognized and treated appropriately. The association of pheochromocytoma and thrombosis is even rarer but significantly increases management complexity, morbidity and mortality. To the best of our knowledge, this is the first report of a patient with pheochromocytoma presenting with left axillary arterial and intracardiac thrombus.</p> <p>Case presentation</p> <p>A 47-year-old Caucasian woman with a past medical history of hypertension presented for medical attention with left arm numbness. Doppler ultrasound showed an obstructing thrombus in her left axillary artery. She had symptom resolution after stent placement in her left axillary artery. A subsequent echocardiogram demonstrated a large intracardiac mass and abdominal computed tomography revealed a 7 cm mass between her spleen and left kidney. Labile blood pressure was noted during admission and she had very high levels of plasma and 24-hour urine catecholamines and metanephrines tests. A (123)I- metaiodobenzylguanidine scan showed intense uptake in the left abdominal mass. After adequate alpha blockage with phenoxybenzamine, laparoscopic tumor resection was performed without complications. She had normal metanephrines and complete symptom resolution afterwards. The intracardiac mass also disappeared with anticoagulation. All other endocrine laboratory abnormalities returned to normal after surgery.</p> <p>Conclusion</p> <p>Arterial and ventricular thrombosis occurring in patients with pheochromocytoma is rare. A multi-disciplinary approach is necessary in caring for this type of patient. Catecholamines likely contributed to the development of thrombosis in our patient. Early recognition of pheochromocytoma is the key to improving outcome.</p
Interleukin-6 gene (IL-6): a possible role in brain morphology in the healthy adult brain
Background: Cytokines such as interleukin 6 (IL-6) have been implicated in dual functions in neuropsychiatric disorders. Little is known about the genetic predisposition to neurodegenerative and neuroproliferative properties of cytokine genes. In this study the potential dual role of several IL-6 polymorphisms in brain morphology is investigated. Methodology: In a large sample of healthy individuals (N = 303), associations between genetic variants of IL-6 (rs1800795; rs1800796, rs2069833, rs2069840) and brain volume (gray matter volume) were analyzed using voxel-based morphometry (VBM). Selection of single nucleotide polymorphisms (SNPs) followed a tagging SNP approach (e.g., Stampa algorigthm), yielding a capture 97.08% of the variation in the IL-6 gene using four tagging SNPs. Principal findings/results: In a whole-brain analysis, the polymorphism rs1800795 (−174 C/G) showed a strong main effect of genotype (43 CC vs. 150 CG vs. 100 GG; x = 24, y = −10, z = −15; F(2,286) = 8.54, puncorrected = 0.0002; pAlphaSim-corrected = 0.002; cluster size k = 577) within the right hippocampus head. Homozygous carriers of the G-allele had significantly larger hippocampus gray matter volumes compared to heterozygous subjects. None of the other investigated SNPs showed a significant association with grey matter volume in whole-brain analyses. Conclusions/significance: These findings suggest a possible neuroprotective role of the G-allele of the SNP rs1800795 on hippocampal volumes. Studies on the role of this SNP in psychiatric populations and especially in those with an affected hippocampus (e.g., by maltreatment, stress) are warranted.Bernhard T Baune, Carsten Konrad, Dominik Grotegerd, Thomas Suslow, Eva Birosova, Patricia Ohrmann, Jochen Bauer, Volker Arolt, Walter Heindel, Katharina Domschke, Sonja Schöning, Astrid V Rauch, Christina Uhlmann, Harald Kugel and Udo Dannlowsk
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