bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ammonia dimer: A surprising structure
Authors: Nelson D. D. , Fraser G. T. , Klemperer W. 
Published: July 2002

High resolution rotational spectra for (14NH3)2, (14ND3)2, 15NH3–14NH3, and 14NH3–15NH3 have been obtained using the molecular beam electric resonance technique. For 14NH3 dimer the spectra are simple and consist only of the J=0–1 and J=1–2 transitions with K=0 for two vibrational states (hereafter designated α and β) of the complex. The spectroscopic constants for (14NH3)2 are: 1/2 (B+C)α=5110.412(2), 1/2 (B+C)β=5110.564(2), DJ=0.0529(5), eqQ1aa =−0.639(13), eqQ2aa =0.904(8) (MHz);  μαa =0.7497(10),  μ βa =0.7376(9) (D). For (ND3)2 the vibrational states are unsplit 1/2 (B+C)=4190.300(50) MHz and  μa=0.567(4) D. These spectroscopic constants are inconsistent with the theoretically predicted structure for NH3 dimer. In the predicted structure one NH3 unit hydrogen bonds to the other with a nearly linear N–H- –N arrangement so that the C3 axis of the basic NH3 is collinear with the hydrogen bond. If θi is the angle between the C3 axis of the ith NH3 unit and the a-inertial axis of the complex, θ1∼0° and θ2∼68° for
the theoretically predicted structure. In contrast, for 14NH3 dimer we measure the average values of θ1 and θ2 as 48.6(1)° and 115.5(1)°, respectively, using the quadrupole hyperfine structure. Furthermore, the component of the dipole moment along the a-inertial axis,  μa, is found to be much smaller (0.75 D) than expected for the theoretical structure (∼2 D). The distance between the centers of mass of the NH3 subunits, RCM, is also determined and is found to be 3.3374(1) Å. No evidence exists for nonrigidity in the ground vibrational state of this complex, i.e., no high frequency tunneling splittings were observed in either the microwave or the infrared spectrum of the complex. The relationship between these structural results and the concept of hydrogen bonding in NH3 systems is discussed. The apparent inability of measured values of heats of formation for NH3 dimer to correctly predict dissociation energies of the complex is also commented upon. The dissociation energy of NH3 dimer has been previously determined as less than 2.8 kcal/mol.
Two-photon double resonance spectroscopy of bacteriorhodopsin. Assignment of the electronic and dipolar properties of the low-lying 1A*−g-like and 1B*+u-like π, π* states
Authors: Birge Robert R. , Zhang Chian-Fan 
Published: July 2002

The electronic and dipolar properties of the all-trans retinyl polyene in light-adapted bacteriorhodopsin are examined by using two-photon double resonance spectroscopy to assign the Franck–Condon maxima, the absolute two-photon absorptivities and the change in dipole moments upon excitation of the low-lying ‘‘forbidden’’ 1A*−g -like and ‘‘allowed’’ 1B*+u -like π, π* excited singlet states. The second-order hyperpolarizability is also determined. The two-photon double resonance spectrum, collected with laser excitation from 820–1200 nm in 10 nm steps, displays two maxima, an intense band at ∼18 000 cm−1 assigned to the 1B*+u -like π, π* excited singlet state and a weaker shoulder at ∼21 000 cm−1 assigned to the 1A*−g -like π, π* excited singlet state. Thus, the 1A*−g -like state is 3500±500 cm−1 above the 1B*+u -like state, which is indicative of a protonated Schiff base chromophore.
A log-normal fit of the two-photon spectrum indicates that the maximum two-photon absorptivity of the 1B*+u -like state is 290±50 GM whereas the maximum two-photon absorptivity of the 1A*−g -like state is less than half this value, 120±90 GM. The ‘‘1B*+u ’’ state exhibits an absorptivity that is dominated by initial and final state contributions to the two-photon tensor, and this observation allows an accurate assignment of the change in dipole moment upon excitation yielding Δμso=13.5±0.8 D. A similar analysis of the ‘‘1A*−g’’ state predicts that the change in dipole moment upon excitation into the latter state is slightly smaller (Δμso=9.1±4.8 D). We demonstrate that the second-order hyperpolarizability of a molecule can be determined directly from the two-photon absorptivity of the low-lying charge transfer state and other spectroscopic parameters, all but one of which can be determined directly from experiment. Our analysis of light adapted bacteriorhodopsin indicates that β=βxxx+(1/3)[βxyy +2βyyx+βxzz+2βzzx] =(2250±240)×10−30cm5/esu for a laser wavelength of 1.06μ assuming that the homogeneous linewidth is 250 cm−1. Preliminary analyses of the two-photon data indicate that the chromophore in bacteriorhodopsin is a protonated Schiff base chromophore in a very ionic, and possibly charged, binding site. The two-photon data are not consistent with charged species near the β-ionylidene ring, but are consistent with polar species near the β-ionylidene ring. Direct hydrogen bonding of a negative counterion with the imine proton is not supported by the two-photon data.
IRES Elements in Connexin Genes: A Hypothesis Explaining the Need for Connexins to Be Regulated at the Translational Level
Authors: Werner Rudolf 
Published: July 2002

AbstractThe fact that stem cells do not express gap junctions while most differentiated cells do suggests that gap junctions serve a vital function in the maintenance of the differentiated state. This would require that connexin genes be expressed even in conditions where cap‐mediated translation is impaired. It is hypothesized that IRES elements in the 5'‐UTRs of the mRNAs of most connexins are required for this purpose.
Architecture and Function of the Human Endonucleases RNase P and RNase MRP
Authors: Van Eenennaam Hans , Jarrous Nayef , van Venrooij Walther J. , Pruijn Ger J. M. 
Published: July 2002

AbstractIn the past decade, important advances have been made in our knowledge of the composition of human RNase MRP and RNase P complexes. Both ribonucleoprotein particles function as endonucleases and contain RNA components that are structurally related. RNase MRP has been suggested to be involved in the processing of precursor rRNA; RNase P, in the maturation of tRNA. Here we give an overview of current data on the structure and function of human RNase MRP and RNase P particles, with emphasis on their molecular composition. At present, seven protein subunits, probably all associated with both ribonucleoprotein particles, have been isolated and their corresponding cDNAs cloned. Although no known structural motifs can be identified in the amino acid sequences of these proteins, the majority is clearly rich in basic residues. For two protein subunits, a cluster of basic amino acids have been shown to be involved in nucleolar accumulation, whereas another protein, which lacks such a region, probably enters the nucleolus by way of a piggyback mechanism. The binding regions for several of the protein subunits on the RNA have been identified, and the data have been used to create a putative structural model for the RNase MRP particle. The rather obscure situation concerning the association of the autoantigenic Th‐40 protein and its possible relationship with one of the subunits, Rpp38, is discussed.
Segregation of Glucosylceramide and Sphingomyelin Occurs in the Apical to Basolateral Transcytotic Route in HepG2 Cells
Authors: IJzendoorn Sven C.D. van , Zegers Mirjam M.P. , Kok Jan Willem , Hoekstra Dick 
Published: July 2002

HepG2 cells are highly differentiated hepatoma cells that have retained an apical, bile canalicular (BC) plasma membrane polarity. We investigated the dynamics of two BC-associated sphingolipids, glucosylceramide (GlcCer) and sphingomyelin (SM). For this, the cells were labeled with fluorescent acyl chainlabeled 6-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)- amino]hexanoic acid (C6-NBD) derivatives of either GlcCer (C6-NBD-GlcCer) or SM (C6-NBD-SM). The pool of the fluorescent lipid analogues present in the basolateral plasma membrane domain was subsequently depleted and the apically located C6-NBD-lipid was chased at 37°C. By using fluorescence microscopical analysis and a new assay that allows an accurate estimation of the fluorescent lipid pool in the apical membrane, qualitative and quantitative insight was obtained concerning kinetics, extent and (intra)cellular sites of the redistribution of apically located C6-NBD-GlcCer and C6-NBD-SM. It is demonstrated that both lipids display a preferential localization, C6-NBD-GlcCer in the apical and C6-NBD-SM in the basolateral area. Such a preference is expressed during transcytosis of both sphingolipids from the apical to the basolateral plasma membrane domain, a novel lipid trafficking route in HepG2 cells. Whereas the vast majority of the apically derived C6-NBD-SM was rapidly transcytosed to the basolateral surface, most of the apically internalized C6-NBD-GlcCer was efficiently redirected to the BC. The redirection of C6-NBD-GlcCer did not involve trafficking via the Golgi apparatus. Evidence is provided which suggests the involvement of vesicular compartments, located subjacent to the apical plasma membrane. Interestingly, the observed difference in preferential localization of C6-NBD-GlcCer and C6NBD-SM was perturbed by treatment of the cells with dibutyryl cAMP, a stable cAMP analogue. While the preferential apical localization of C6-NBD-GlcCer was amplified, dibutyryl cAMP-treatment caused apically retrieved C6-NBD-SM to be processed via a similar pathway as that of C6-NBD-GlcCer.
The data unambiguously demonstrate that segregation of GlcCer and SM occurs in the reverse transcytotic route, i.e., during apical to basolateral transport, which results in the preferential localization of GlcCer and SM in the apical and basolateral region of the cells, respectively. A role for non-Golgi–related, sub-apical vesicular compartments in the sorting of GlcCer and SM is proposed.
J-Express: exploring gene expression data using Java
Authors: Dysvik B. , Jonassen I. 
Published: July 2002

Abstract
Summary: J-Express is a Java application that allows the user to analyze gene expression (microarray) data in a flexible way giving access to multidimensional scaling, clustering, and visualization methods in an integrated manner. Specifically, J-Express includes implementations of hierarchical clustering, k-means, principal component analysis, and self-organizing maps. At present, it does not include methods for comparing two or more experiments for differentially expressed genes. The application is completely portable and requires only that a Java runtime environment 1.2 is installed on the system. Its efficiency allows interactive clustering of thousands of expression profiles on standard personal computers.
Availability: http://www.ii.uib.no/~bjarted/jexpress/
Contact: bjarted@ii.uib.no
* To whom correspondence should be addressed.
HOMSTRAD: adding sequence information to structure-based
alignments of homologous protein families
Authors: de Bakker P. I. W. , Bateman A. , Burke D. F. , Miguel R. N. , Mizuguchi K. , Shi J. , Shirai H. , Blundell T. L. 
Published: July 2002

Abstract
Summary: We describe an extension to the Homologous Structure Alignment Database (HOMSTRAD; Mizuguchi et al. , Protein Sci. , 7, 2469–2471, 1998a) to include homologous sequences derived from the protein families database Pfam (Bateman et al. , Nucleic Acids Res. , 28, 263–266, 2000). HOMSTRAD is integrated with the server FUGUE (Shi et al. , submitted, 2001) for recognition and alignment of homologues, benefitting from the combination of abundant sequence information and accurate structure-based alignments.
Availability: The HOMSTRAD database is available at: http://www-cryst.bioc.cam.ac.uk/homstrad/. Query sequences can be submitted to the homology recognition/alignment server FUGUE at: http://www-cryst.bioc.cam.ac.uk/fugue/.
Contact: homstrad@cryst.bioc.cam.ac.uk
Weight Loss Outcomes Associated With Semaglutide Treatment for Patients With Overweight or Obesity
Authors: Ghusn Wissam , De la Rosa Alan , Sacoto Daniel , Cifuentes Lizeth , Campos Alejandro , Feris Fauzi , Hurtado Maria Daniela , Acosta Andres 
Published: September 2022

ImportanceNo retrospective cohort study has assessed the effectiveness of semaglutide at doses used in randomized clinical trials to treat obesity (ie, 1.7 and 2.4 mg).ObjectiveTo study weight loss outcomes associated with semaglutide treatment at doses used in randomized clinical trials for patients with overweight or obesity.Design, Setting, and ParticipantsThis cohort study, conducted at a referral center for weight management, retrospectively collected data on the use of semaglutide for adults with overweight or obesity between January 1, 2021, and March 15, 2022, with a follow-up of up to 6 months. A total of 408 patients with a body mass index (BMI) of 27 or more were prescribed weekly semaglutide subcutaneous injections for 3 months or more. Patients with a history of bariatric procedures, taking other antiobesity medications, and with an active malignant neoplasm were excluded.ExposuresWeekly 1.7-mg or 2.4-mg semaglutide subcutaneous injections for 3 to 6 months.Main Outcomes and MeasuresThe primary end point was the percentage of weight loss. Secondary end points were the proportion of patients achieving weight loss of 5% or more, 10% or more, 15% or more, and 20% or more after 3 and 6 months and the percentage of weight loss for patients with or without type 2 diabetes after 3 and 6 months.ResultsThe study included 175 patients (132 women [75.4%]; mean [SD] age, 49.3 [12.5] years; mean [SD] BMI, 41.3 [9.1]) in the analysis at 3 months and 102 patients at 6 months. The mean (SD) weight loss after 3 months was 6.7 (4.4) kg, equivalent to a mean (SD) weight loss of 5.9% (3.7%) (P &lt; .001), and the mean (SD) weight loss after 6 months was 12.3 (6.6) kg, equivalent to a mean (SD) weight loss of 10.9% (5.8%) (P &lt; .001 from baseline). Of the 102 patients who were followed up at 6 months, 89 (87.3%) achieved weight loss of 5% or more, 56 (54.9%) achieved weight loss of 10% or more, 24 (23.5%) achieved weight loss of 15% or more, and 8 (7.8%) achieved weight loss of 20% or more. Patients with type 2 diabetes had a lower mean (SD) percentage weight loss at 3 and 6 months compared with those without type 2 diabetes: 3.9% (3.1%) vs 6.3% (3.7%) at 3 months (P = .001) and 7.2% (6.3%) vs 11.8% (5.3%) at 6 months (P = .005).Conclusions and RelevanceThe results of this cohort study suggest that weekly 1.7-mg and 2.4-mg doses of semaglutide were associated with weight loss similar to that seen in randomized clinical trials. Studies with longer periods of follow-up are needed to evaluate prolonged weight loss outcomes.
Efficacy and Safety of Rituximab for New-Onset Generalized Myasthenia Gravis
Authors: Piehl Fredrik , Eriksson-Dufva Ann , Budzianowska Anna , Feresiadou Amalia , Hansson William , Hietala Max Albert , Håkansson Irene , Johansson Rune , Jons Daniel , Kmezic Ivan , Lindberg Christopher , Lindh Jonas , Lundin Fredrik , Nygren Ingela , Punga Anna Rostedt , Press Rayomand , Samuelsson Kristin , Sundström Peter , Wickberg Oskar , Brauner Susanna , Frisell Thomas 
Published: September 2022

ImportanceRituximab is a third-line option for refractory generalized myasthenia gravis (MG) based on empirical evidence, but its effect in new-onset disease is unknown.ObjectiveTo investigate the efficacy and safety of rituximab compared with placebo as an add-on to standard of care for MG.Design, Setting, and ParticipantsThis randomized, double-blind, placebo-controlled study took place throughout 48 weeks at 7 regional clinics in Sweden. Key inclusion criteria were age older than 18 years, onset of generalized symptoms within 12 months or less, and a Quantitative Myasthenia Gravis (QMG) score of 6 or more. Patients were screened from October 20, 2016, to March 2, 2020. Key exclusion criteria included pure ocular MG, suspected thymoma, previous thymectomy, and prior noncorticosteroid immunosuppressants or high doses of corticosteroids.InterventionsParticipants were randomized 1:1 without stratification to a single intravenous infusion of 500 mg of rituximab or matching placebo.Main Outcomes and MeasuresMinimal disease manifestations at 16 weeks defined as a QMG score of 4 or less with prednisolone, 10 mg or less daily, and no rescue treatment.ResultsOf 87 potentially eligible patients, 25 were randomized to rituximab (mean [SD] age, 67.4 [13.4] years; 7 [28%] female) and 22 to placebo (mean [SD] age, 58 [18.6] years; 7 [32%] female). Compared with placebo, a greater proportion with rituximab met the primary end point; 71% (17 of 24) in the rituximab group vs 29% (6 of 21) in the placebo group (Fisher exact test P = .007; probability ratio, 2.48 [95% CI, 1.20-5.11]). Secondary end points, comparing changes in Myasthenia Gravis Activities of Daily Living and Myasthenia Gravis Quality of Life at 16 weeks with QMG at 24 weeks did not differ between groups with censoring for rescue treatment (per-protocol analysis) but were in favor of active treatment when rescue treatment was taken into account by worst rank imputation (post hoc analysis). Rescue treatments were also more frequent in the placebo arm (rituximab: 1 [4%]; placebo, 8 [36%]). One patient in the placebo arm had a myocardial infarction with cardiac arrest and 1 patient in the active arm experienced a fatal cardiac event.Conclusions and RelevanceA single dose of 500 mg of rituximab was associated with greater probability of minimal MG manifestations and reduced need of rescue medications compared with placebo. Further studies are needed to address long-term benefit-risk balance with this treatment.Trial RegistrationClinicalTrials.gov Identifier: NCT02950155
Association of Early Oseltamivir With Improved Outcomes in Hospitalized Children With Influenza, 2007-2020
Authors: Walsh Patrick S. , Schnadower David , Zhang Yin , Ramgopal Sriram , Shah Samir S. , Wilson Paria M. 
Published: September 2022

ImportanceOseltamivir is recommended for all children hospitalized with influenza, despite limited evidence supporting its use in the inpatient setting.ObjectiveTo determine whether early oseltamivir use is associated with improved outcomes in children hospitalized with influenza.Design, Setting, and ParticipantsThis multicenter retrospective study included 55 799 children younger than 18 years who were hospitalized with influenza from October 1, 2007, to March 31, 2020, in 36 tertiary care pediatric hospitals who participate in the Pediatric Health Information System database. Data were analyzed from January 2021 to March 2022.ExposuresEarly oseltamivir treatment, defined as use of oseltamivir on hospital day 0 or 1.Main Outcomes and MeasuresThe primary outcome was hospital length of stay (LOS) in calendar days. Secondary outcomes included 7-day hospital readmission, late (hospital day 2 or later) intensive care unit (ICU) transfer, and a composite outcome of in-hospital death or use of extracorporeal membrane oxygenation (ECMO). Inverse probability treatment weighting (IPTW) based on propensity scoring was used to address confounding by indication. Mixed-effects models were used to compare outcomes between children who did and did not receive early oseltamivir treatment. Outcomes were also compared within high-risk subgroups based on age, presence of a complex chronic condition, early critical illness, and history of asthma.ResultsThe analysis included 55 799 encounters from 36 hospitals. The median (IQR) age of the cohort was 3.61 years (1.03-8.27); 56% were male, and 44% were female. A total of 33 207 patients (59.5%) received early oseltamivir. In propensity score–weighted models, we found that children treated with early oseltamivir had shorter LOS (median 3 vs 4 days; IPTW model ratio, 0.52; 95% CI, 0.52-0.53) and lower odds of all-cause 7-day hospital readmission (3.5% vs 4.8%; adjusted odds ratio [aOR], 0.72; 95% CI, 0.66-0.77), late ICU transfer (2.4% vs 5.5%; aOR, 0.41; 95% CI, 0.37-0.46), and the composite outcome of death or ECMO use (0.9% vs 1.4%; aOR, 0.63; 95% CI, 0.54-0.73).Conclusions and RelevanceEarly use of oseltamivir in hospitalized children was associated with shorter hospital stay and lower odds of 7-day readmission, ICU transfer, ECMO use, and death. These findings support the current recommendations for oseltamivir use in children hospitalized with influenza.
Spintronic Physical Unclonable Functions Based on Field‐Free Spin–Orbit‐Torque Switching
Authors: Lee Soogil , Kang Jaimin , Kim Jeong‐Mok , Kim Namhee , Han Donghyeon , Lee Taekhyeon , Ko San , Yang Jiseok , Lee Sanghwa , Lee Sungjun , Koh Daekyu , Kang Min‐Gu , Lee Jisung , Noh Sujung , Lee Hansaem , Kwon JoonHyun , Baek Seung‐heon Chris , Kim Kab‐Jin , Park Byong‐Guk 
Published: September 2022

AbstractPhysical unclonable function (PUFs) utilize inherent random physical variations of solid‐state devices and are a core ingredient of hardware security primitives. PUFs promise more robust information security than that provided by the conventional software‐based approaches. While silicon‐ and memristor‐based PUFs are advancing, their reliability and scalability require further improvements. These are currently limited by output fluctuations and associated additional peripherals. Here, highly reliable spintronic PUFs that exploit field‐free spin–orbit‐torque switching in IrMn/CoFeB/Ta/CoFeB structures are demonstrated. It is shown that the stochastic switching polarity of the perpendicular magnetization of the top CoFeB can be achieved by manipulating the exchange bias directions of the bottom IrMn/CoFeB. This serves as an entropy source for the spintronic PUF, which is characterized by high entropy, uniqueness, reconfigurability, and digital output. Furthermore, the device ensures a zero bit‐error‐rate under repetitive operations and robustness against external magnetic fields, and offers scalable and energy‐efficient device implementations.
Supramolecular Engineering of Amorphous Porous Polymers for Rapid Adsorption of Micropollutants and Solar‐Powered Volatile Organic Compounds Management
Authors: Cho Wansu , Lee Dongjun , Choi Gyeonghyeon , Kim Jihyo , Kojo Acquah Ebenezer , Park Chiyoung 
Published: September 2022

AbstractFreshwater shortage is becoming one of the most critical global challenges owing to severe water pollution caused by micropollutants and volatile organic compounds (VOCs). However, current purification technology shows slow adsorption of micropollutants and requires an energy‐intensive process for VOCs removal from water. In this study, a highly efficient molecularly engineered covalent triazine framework (CTF) for rapid adsorption of micropollutants and VOC‐intercepting performance using solar distillation is reported. Supramolecular design and mild oxidation of CTFs (CTF‐OXs) enable hydrophilic internal channels and improve molecular sieving of micropollutants. CTF‐OX shows rapid removal efficiency of micropollutants (>99.9% in 10 s) and can be regenerated several times without performance loss. Uptake rates of selected micropollutants are high, with initial pollutant uptake rates of 21.9 g mg−1 min−1, which are the highest rates recorded for bisphenol A (BPA) adsorption. Additionally, photothermal composite membrane fabrication using CTF‐OX exhibits high VOC rejection rate (up to 98%) under 1 sun irradiation (1 kW m−2). A prototype of synergistic purification system composed of adsorption and solar‐driven membrane can efficiently remove over 99.9% of mixed phenol derivatives. This study provides an effective strategy for rapid removal of micropollutants and high VOC rejection via solar‐driven evaporation process.