Possible origins of macroscopic left-right asymmetry in organisms

I consider the microscopic mechanisms by which a particular left-right (L/R) asymmetry is generated at the organism level from the microscopic handedness of cytoskeletal molecules. In light of a fundamental symmetry principle, the typical pattern-formation mechanisms of diffusion plus regulation cannot implement the "right-hand rule"; at the microscopic level, the cell's cytoskeleton of chiral filaments seems always to be involved, usually in collective states driven by polymerization forces or molecular motors. It seems particularly easy for handedness to emerge in a shear or rotation in the background of an effectively two-dimensional system, such as the cell membrane or a layer of cells, as this requires no pre-existing axis apart from the layer normal. I detail a scenario involving actin/myosin layers in snails and in C. elegans, and also one about the microtubule layer in plant cells. I also survey the other examples that I am aware of, such as the emergence of handedness such as the emergence of handedness in neurons, in eukaryote cell motility, and in non-flagellated bacteria.Comment: 42 pages, 6 figures, resubmitted to J. Stat. Phys. special issue. Major rewrite, rearranged sections/subsections, new Fig 3 + 6, new physics in Sec 2.4 and 3.4.1, added Sec 5 and subsections of Sec

Aortic distensibility and coronary artery bypass graft patency

<p>Abstract</p> <p>Background</p> <p>Aortic distensibility is an elasticity index of the aorta, and reflects aortic stiffness. Coronary artery disease has been found to be substantially associated with increased aortic stiffness. In this study we aimed to retrospectively analyze the association of angiographically determined aortic distensibility with the patency rates of coronary bypass grafts</p> <p>Methods</p> <p>The study was conducted in the Cardiology department of the Applied Research Centre for Health of Uludağ University. The coronary angiograms of 53 consecutive coronary bypass patients were analysed retrospectively. Aortic distensibility was calculated using the formula: 2 × (change in aortic diameter)/(diastolic aortic diameter) × (change in aortic pressure). The number of stenosed and patent bypass grafts and the patient characteristics like age, risk factors were noted.</p> <p>Results</p> <p>There were 44 male (83%) and 9 female (17%) cases. Eighteen cases had only one saphenous vein grafting. The number of cases with two, three and four saphenous grafting were 18, 11 and 1; respectively. In the control angiograms the number of cases with one, two, three and four saphenous vein graft obstruction were 15 (31.3%), 7 (14.6%), 1 (2.1%) and 1 (2.1%) respectively. The aortic distensibility did not differ in cases with and without saphenous graft occlusion (p > 0.05). Also left internal mammary artery (LIMA) graft patency was not related to the distensibility of the aorta (p > 0.05). We also evaluated the data for cut-off values of 50 and 70 mmHg of pulse pressure and did not see any significant difference between the groups in terms of saphenous or LIMA grafts.</p> <p>Conclusion</p> <p>In this study we failed to show association of angiographically determined aortic distensibility with coronary bypass graft patency in consecutive 53 patients with coronary artery bypass graft surgery (CABG).</p

Outcome of COVID-19 in Patients With Autoimmune Hepatitis: An International Multicenter Study

Background and Aims: Data regarding outcome of COVID-19 in patients with autoimmune hepatitis (AIH) are lacking. Approach and Results: We performed a retrospective study on patients with AIH and COVID-19 from 34 centers in Europe and the Americas. We analyzed factors associated with severe COVID-19 outcomes, defined as the need for mechanical ventilation, intensive care admission, and/or death. The outcomes of patients with AIH were compared to a propensity score?matched cohort of patients without AIH but with chronic liver diseases (CLD) and COVID-19. The frequency and clinical significance of new-onset liver injury (alanine aminotransferase > 2 × the upper limit of normal) during COVID-19 was also evaluated. We included 110 patients with AIH (80% female) with a median age of 49 (range, 18-85) years at COVID-19 diagnosis. New-onset liver injury was observed in 37.1% (33/89) of the patients. Use of antivirals was associated with liver injury (P = 0.041; OR, 3.36; 95% CI, 1.05-10.78), while continued immunosuppression during COVID-19 was associated with a lower rate of liver injury (P = 0.009; OR, 0.26; 95% CI, 0.09-0.71). The rates of severe COVID-19 (15.5% versus 20.2%, P = 0.231) and all-cause mortality (10% versus 11.5%, P = 0.852) were not different between AIH and non-AIH CLD. Cirrhosis was an independent predictor of severe COVID-19 in patients with AIH (P < 0.001; OR, 17.46; 95% CI, 4.22-72.13). Continuation of immunosuppression or presence of liver injury during COVID-19 was not associated with severe COVID-19. Conclusions: This international, multicenter study reveals that patients with AIH were not at risk for worse outcomes with COVID-19 than other causes of CLD. Cirrhosis was the strongest predictor for severe COVID-19 in patients with AIH. Maintenance of immunosuppression during COVID-19 was not associated with increased risk for severe COVID-19 but did lower the risk for new-onset liver injury during COVID-19.Fil: Efe, Cumali. Harran University Hospital; TurquíaFil: Dhanasekaran, Renumathy. University of Stanford; Estados UnidosFil: Lammert, Craig. University School of Medicine; Estados UnidosFil: Ebik, Berat. Gazi Yaşargil Education and Research Hospital; TurquíaFil: Higuera de la Tijera, Fatima. Hospital General de México; MéxicoFil: Aloman, Costica. Rush University Medical Center; Estados UnidosFil: Rıza Calışkan, Ali. Adıyaman University; TurquíaFil: Peralta, Mirta. Latin American Liver Research Educational And Awareness Network; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital de Infecciosas "Dr. Francisco Javier Muñiz"; ArgentinaFil: Gerussi, Alessio. University of Milano Bicocca; Italia. San Gerardo Hospital; ItaliaFil: Massoumi, Hatef. Montefiore Medical Center; Estados UnidosFil: Catana, Andreea M.. Harvard Medical School; Estados UnidosFil: Torgutalp, Murat. Universitätsmedizin Berlin; AlemaniaFil: Purnak, Tugrul. McGovern Medical School; Estados UnidosFil: Rigamonti, Cristina. Azienda Ospedaliera Maggiore Della Carita Di Novara; Italia. Università del Piemonte Orientale; ItaliaFil: Gomez Aldana, Andres Jose. Universidad de los Andes; ColombiaFil: Khakoo, Nidah. University of Miami; Estados UnidosFil: Kacmaz, Hüseyin. Adıyaman University; TurquíaFil: Nazal, Leyla. Clínica Las Condes; ChileFil: Frager, Shalom. Montefiore Medical Center; Estados UnidosFil: Demir, Nurhan. Haseki Training and Research Hospita; TurquíaFil: Irak, Kader. SBU Kanuni Sultan Süleyman Training and Research Hospital; TurquíaFil: Ellik, Zeynep Melekoğlu. Ankara University Medical Faculty; TurquíaFil: Balaban, Yasemin. Hacettepe University; TurquíaFil: Atay, Kadri. Mardin State Hospital; TurquíaFil: Eren, Fatih. Ordu State Hospital; TurquíaFil: Cristoferi, Laura. University of Milano Bicocca; Italia. San Gerardo Hospital; ItaliaFil: Batibay, Ersin. Harran University Hospital; TurquíaFil: Urzua, Álvaro. Universidad de Chile. Facultad de Medicina.; ChileFil: Snijders, Romee. Radboud University Medical Center; Países BajosFil: Ridruejo, Ezequiel. Latin American Liver Research Educational and Awareness Network; Argentina. Cerrahpaşa School of Medicine; Turquía. Centro de Educación Médica e Investigaciones Clínicas "Norberto Quirno"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Effects of immunosuppressive drugs on COVID-19 severity in patients with autoimmune hepatitis

Background: We investigated associations between baseline use of immunosuppressive drugs and severity of Coronavirus Disease 2019 (COVID-19) in autoimmune hepatitis (AIH). Patients and methods: Data of AIH patients with laboratory confirmed COVID-19 were retrospectively collected from 15 countries. The outcomes of AIH patients who were on immunosuppression at the time of COVID-19 were compared to patients who were not on AIH medication. The clinical courses of COVID-19 were classified as (i)-no hospitalization, (ii)-hospitalization without oxygen supplementation, (iii)-hospitalization with oxygen supplementation by nasal cannula or mask, (iv)-intensive care unit (ICU) admission with non-invasive mechanical ventilation, (v)-ICU admission with invasive mechanical ventilation or (vi)-death and analysed using ordinal logistic regression. Results: We included 254 AIH patients (79.5%, female) with a median age of 50 (range, 17-85) years. At the onset of COVID-19, 234 patients (92.1%) were on treatment with glucocorticoids (n = 156), thiopurines (n = 151), mycophenolate mofetil (n = 22) or tacrolimus (n = 16), alone or in combinations. Overall, 94 (37%) patients were hospitalized and 18 (7.1%) patients died. Use of systemic glucocorticoids (adjusted odds ratio [aOR] 4.73, 95% CI 1.12-25.89) and thiopurines (aOR 4.78, 95% CI 1.33-23.50) for AIH was associated with worse COVID-19 severity, after adjusting for age-sex, comorbidities and presence of cirrhosis. Baseline treatment with mycophenolate mofetil (aOR 3.56, 95% CI 0.76-20.56) and tacrolimus (aOR 4.09, 95% CI 0.69-27.00) were also associated with more severe COVID-19 courses in a smaller subset of treated patients. Conclusion: Baseline treatment with systemic glucocorticoids or thiopurines prior to the onset of COVID-19 was significantly associated with COVID-19 severity in patients with AIH.Fil: Efe, Cumali. Harran University Hospita; TurquíaFil: Lammert, Craig. University School of Medicine Indianapolis; Estados UnidosFil: Taşçılar, Koray. Universitat Erlangen-Nuremberg; AlemaniaFil: Dhanasekaran, Renumathy. University of Stanford; Estados UnidosFil: Ebik, Berat. Gazi Yasargil Education And Research Hospital; TurquíaFil: Higuera de la Tijera, Fatima. Hospital General de México; MéxicoFil: Calışkan, Ali R.. No especifíca;Fil: Peralta, Mirta. Gobierno de la Ciudad de Buenos Aires. Hospital de Infecciosas "Dr. Francisco Javier Muñiz"; ArgentinaFil: Gerussi, Alessio. Università degli Studi di Milano; ItaliaFil: Massoumi, Hatef. No especifíca;Fil: Catana, Andreea M.. Harvard Medical School; Estados UnidosFil: Purnak, Tugrul. University of Texas; Estados UnidosFil: Rigamonti, Cristina. Università del Piemonte Orientale ; ItaliaFil: Aldana, Andres J. G.. Fundacion Santa Fe de Bogota; ColombiaFil: Khakoo, Nidah. Miami University; Estados UnidosFil: Nazal, Leyla. Clinica Las Condes; ChileFil: Frager, Shalom. Montefiore Medical Center; Estados UnidosFil: Demir, Nurhan. Haseki Training And Research Hospital; TurquíaFil: Irak, Kader. Kanuni Sultan Suleyman Training And Research Hospital; TurquíaFil: Melekoğlu Ellik, Zeynep. Ankara University Medical Faculty; TurquíaFil: Kacmaz, Hüseyin. Adıyaman University; TurquíaFil: Balaban, Yasemin. Hacettepe University; TurquíaFil: Atay, Kadri. No especifíca;Fil: Eren, Fatih. No especifíca;Fil: Alvares da-Silva, Mario R.. Universidade Federal do Rio Grande do Sul; BrasilFil: Cristoferi, Laura. Università degli Studi di Milano; ItaliaFil: Urzua, Álvaro. Universidad de Chile; ChileFil: Eşkazan, Tuğçe. Cerrahpaşa School of Medicine; TurquíaFil: Magro, Bianca. No especifíca;Fil: Snijders, Romee. No especifíca;Fil: Barutçu, Sezgin. No especifíca;Fil: Lytvyak, Ellina. University of Alberta; CanadáFil: Zazueta, Godolfino M.. Instituto Nacional de la Nutrición Salvador Zubiran; MéxicoFil: Demirezer Bolat, Aylin. Ankara City Hospital; TurquíaFil: Aydın, Mesut. Van Yuzuncu Yil University; TurquíaFil: Amorós Martín, Alexandra Noemí. No especifíca;Fil: De Martin, Eleonora. No especifíca;Fil: Ekin, Nazım. No especifíca;Fil: Yıldırım, Sümeyra. No especifíca;Fil: Yavuz, Ahmet. No especifíca;Fil: Bıyık, Murat. Necmettin Erbakan University; TurquíaFil: Narro, Graciela C.. Instituto Nacional de la Nutrición Salvador Zubiran; MéxicoFil: Bıyık, Murat. Uludag University; TurquíaFil: Kıyıcı, Murat. No especifíca;Fil: Kahramanoğlu Aksoy, Evrim. No especifíca;Fil: Vincent, Maria. No especifíca;Fil: Carr, Rotonya M.. University of Pennsylvania; Estados UnidosFil: Günşar, Fulya. No especifíca;Fil: Reyes, Eira C.. Hepatology Unit. Hospital Militar Central de México; MéxicoFil: Harputluoğlu, Murat. Inönü University School of Medicine; TurquíaFil: Aloman, Costica. Rush University Medical Center; Estados UnidosFil: Gatselis, Nikolaos K.. University Hospital Of Larissa; GreciaFil: Üstündağ, Yücel. No especifíca;Fil: Brahm, Javier. Clinica Las Condes; ChileFil: Vargas, Nataly C. E.. Hospital Nacional Almanzor Aguinaga Asenjo; PerúFil: Güzelbulut, Fatih. No especifíca;Fil: Garcia, Sandro R.. Hospital Iv Víctor Lazarte Echegaray; PerúFil: Aguirre, Jonathan. Hospital Angeles del Pedregal; MéxicoFil: Anders, Margarita. Hospital Alemán; ArgentinaFil: Ratusnu, Natalia. Hospital Regional de Ushuaia; ArgentinaFil: Hatemi, Ibrahim. No especifíca;Fil: Mendizabal, Manuel. Universidad Austral; ArgentinaFil: Floreani, Annarosa. Università di Padova; ItaliaFil: Fagiuoli, Stefano. No especifíca;Fil: Silva, Marcelo. Universidad Austral; ArgentinaFil: Idilman, Ramazan. No especifíca;Fil: Satapathy, Sanjaya K.. No especifíca;Fil: Silveira, Marina. University of Yale. School of Medicine; Estados UnidosFil: Drenth, Joost P. H.. No especifíca;Fil: Dalekos, George N.. No especifíca;Fil: N.Assis, David. University of Yale. School of Medicine; Estados UnidosFil: Björnsson, Einar. No especifíca;Fil: Boyer, James L.. University of Yale. School of Medicine; Estados UnidosFil: Yoshida, Eric M.. University of British Columbia; CanadáFil: Invernizzi, Pietro. Università degli Studi di Milano; ItaliaFil: Levy, Cynthia. University of Miami; Estados UnidosFil: Montano Loza, Aldo J.. University of Alberta; CanadáFil: Schiano, Thomas D.. No especifíca;Fil: Ridruejo, Ezequiel. Universidad Austral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET; ArgentinaFil: Wahlin, Staffan. No especifíca

Search for resonances in the mass spectrum of muon pairs produced in association with b quark jets in proton-proton collisions at root 8 and 13 TeV

A search for resonances in the mass range 12-70 GeV produced in association with a b quark jet and a second jet, and decaying to a muon pair, is reported. The analysis is based on data from proton-proton collisions at center-of-mass energies of 8 and 13 TeV, collected with the CMS detector at the LHC and corresponding to integrated luminosities of 19.7 and 35.9 fb(-1), respectively. The search is carried out in two mutually exclusive event categories. Events in the first category are required to have a b quark jet in the central region (|| 2.4) and at least one jet in the forward region (|| > 2.4). Events in the second category are required to have two jets in the central region, at least one of which is identified as a b quark jet, no jets in the forward region, and low missing transverse momentum. An excess of events above the background near a dimuon mass of 28 GeV is observed in the 8 TeV data, corresponding to local significances of 4.2 and 2.9 standard deviations for the first and second event categories, respectively. A similar analysis conducted with the 13 TeV data results in a mild excess over the background in the first event category corresponding to a local significance of 2.0 standard deviations, while the second category results in a 1.4 standard deviation deficit. The fiducial cross section measurements and 95% confidence level upper limits on those for a resonance consistent with the 8 TeV excess are provided at both collision energies

Search for top squark pair production in pp collisions at root s=13 TeV using single lepton events

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Search for narrow resonances in dilepton mass spectra in proton-proton collisions at root s=13 TeV and combination with 8 TeV data

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Search for new physics with dijet angular distributions in proton-proton collisions at root S = 13 TeV

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Observation of Charge-Dependent Azimuthal Correlations in p-Pb Collisions and Its Implication for the Search for the Chiral Magnetic Effect

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Search for supersymmetry in proton-proton collisions at 13 TeV using identified top quarks

A search for supersymmetry is presented based on proton-proton collision events containing identified hadronically decaying top quarks, no leptons, and an imbalance p(T)(miss) in transverse momentum. The data were collected with the CMS detector at the CERN LHC at a center-of-mass energy of 13 TeV, and correspond to an integrated luminosity of 35.9 fb(-1). Search regions are defined in terms of the multiplicity of bottom quark jet and top quark candidates, the p(T)(miss) , the scalar sum of jet transverse momenta, and themT2 mass variable. No statistically significant excess of events is observed relative to the expectation from the standard model. Lower limits on the masses of supersymmetric particles are determined at 95% confidence level in the context of simplified models with top quark production. For a model with direct top squark pair production followed by the decay of each top squark to a top quark and a neutralino, top squark masses up to 1020 GeVand neutralino masses up to 430 GeVare excluded. For amodel with pair production of gluinos followed by the decay of each gluino to a top quark-antiquark pair and a neutralino, gluino masses up to 2040 GeVand neutralino masses up to 1150 GeVare excluded. These limits extend previous results.Peer reviewe