bluuebunny/crossref_metadata_2025 huggingface dataset:
A Queueing Theory Model of Nonstationary Traffic Flow
Authors: Heidemann Dirk
Published: December 2003

The queueing-theoretical model for stationary traffic flow developed in a former paper is extended and modified for nonstationary flow. In particular it is shown how speed-flow-density relationships under nonstationary conditions may deviate from those obtained for stationary conditions. It is shown how the wide scatter which is often observed with empirical speed-flow-density data can be explained by nonstationarity. Furthermore, hysteresis loops, which may show up in speed-flow-density relationships, are interpreted by means of nonstationarity.
A Weighted Autoregressive Model to Improve Mobile Emissions Estimates for Locations with Spatial Dependence
Authors: Kim Sung-Eun , Niemeier Debbie
Published: December 2003

For air quality analysis, travel demand model output must be converted to the fine-grained spatial and temporal resolution required by the photochemical models. In particular, network link volume estimates by modeling period (i.e., AM, PM, off-peak) must be converted to hourly profiles. New methods for accomplishing this have not taken spatial autocorrelation into account. This research proposes a weighted autoregressive model for estimating hourly profiles when geographic ordering (i.e., links on a network) is present. An iterative maximum likelihood estimation procedure is developed and used to estimate allocation factors, which disaggregate period-based travel demand model assignments into hourly profiles, for San Diego. Three different forms of the weight matrix, W 1 (binary), W 2 (reciprocal distance), and W 3 (combination of W 1 and W 2), are tested in the analysis. The results indicate that autocorrelation from geographic ordering can be eliminated with the proposed technique.
Delivery Cost Approximations for Inventory Routing Problems in a Rolling Horizon Framework
Authors: Jaillet Patrick , Bard Jonathan F. , Huang Liu , Dror Moshe
Published: December 2003

The inventory routing problem considered in this paper is concerned with the repeated distribution of a commodity, such as heating oil, over a long period of time to a large number of customers. The problem involves a central depot as well as various satellite facilities which the drivers can visit during their shift to refill their vehicles. The customers maintain a local inventory of the commodity. Their consumption varies daily and cannot be predicted deterministically. In case of a stockout, a direct delivery is made and a penalty cost is incurred. In this paper, we present incremental cost approximations to be used in a rolling horizon framework for the problem of minimizing the total expected annual delivery costs.
Continuous and Discrete Shipping Strategies for the Single Link Problem
Authors: Bertazzi Luca , Speranza Maria Grazia
Published: December 2003

We consider the problem of shipping several products from a common origin to a common destination. Each product is offered at the origin and absorbed at the destination at a given constant rate. The objective of the problem is to determine a shipping strategy that minimizes the sum of the transportation and the inventory costs. We present a general framework of analysis from which we derive the known approaches with a continuous frequency and with a set of given frequencies as particular cases. Moreover, we derive from the general framework a new model for the case with discrete shipping times in which a shipment can take place at each discrete time instant. We prove that the optimal solutions of the three models can be ranked and that the distance between the optimal costs can be unlimited in the worst case. Finally, we evaluate, on the basis of a set of randomly generated problem instances, the "average" distance between the optimal solutions of the models.
Models and Methods for Merge-in-Transit Operations
Authors: Croxton Keely L. , Gendron Bernard , Magnanti Thomas L.
Published: December 2003

We develop integer programming formulations and solution methods for addressing operational issues in merge-in-transit distribution systems. The models account for various complex problem features, including the integration of inventory and transportation decisions, the dynamic and multimodal components of the application, and the nonconvex piecewise linear structure of the cost functions. To accurately model the cost functions, we introduce disaggregation techniques that allow us to derive a hierarchy of linear programming relaxations. To solve these relaxations, we propose a cutting-plane procedure that combines constraint and variable generation with rounding and branch-and-bound heuristics. We demonstrate the effectiveness of this approach on a large set of test problems with instances derived from actual data from the computer industry that contain almost 500,000 integer variables.
A Joint Location-Inventory Model
Authors: Shen Zuo-Jun Max , Coullard Collette , Daskin Mark S.
Published: December 2003

We consider a joint location-inventory problem involving a single supplier and multiple retailers. Associated with each retailer is some variable demand. Due to this variability, some amount of safety stock must be maintained to achieve suitable service levels. However, risk-pooling benefits may be achieved by allowing some retailers to serve as distribution centers (and therefore inventory storage locations) for other retailers. The problem is to determine which retailers should serve as distribution centers and how to allocate the other retailers to the distribution centers. We formulate this problem as a nonlinear integer-programming model. We then restructure this model into a set-covering integer-programming model. The pricing problem that must be solved as part of the column generation algorithm for the set-covering model involves a nonlinear term in the retailerdistribution-center allocation terms. We show that this pricing problem can (theoretically) be solved efficiently, in general, and we show how to solve it practically in two important cases. We present computational results on several instances of sizes ranging from 33 to 150 retailers. In all cases, the lower bound from the linear-programming relaxation to the set-covering model gives the optimal solution.
A Whole-Link Travel-Time Model with Desirable Properties
Authors: Carey Malachy , Ge Y. E. , McCartney Mark
Published: December 2003

In network models for dynamic traffic assignment the link travel times are often described by “whole-link” models. In particular, they have been expressed as a function of the number of vehicles currently on the link. Such whole-link models are useful approximations and make the network model tractable when flows and travel times are varying over time. Here we propose an alternative whole-link model to approximate travel times. For a vehicle entering a link at time t, we let the link travel time be a function of a weighted average of the inflow rate at the time it enters and the outflow rate at the time it exits. We show that this model ensures first-in-first-out and has other desirable properties. We indicate computational methods for solving the model, apply it to various patterns of inflows, and compare the numerical results with two alternative whole-link models.
Vehicle Routing and Scheduling with Full Truckloads
Authors: Arunapuram Sundararajan , Mathur Kamlesh , Solow Daniel
Published: December 2003

Truckload carriers are constantly faced with the problem of shipping full truckloads of goods at minimum cost between pairs of cities or customers, using a fleet of trucks located at one or more depots. In this paper, a new branch-and-bound algorithm for solving an integer-programming formulation of this vehicle-routing problem (VRP) with full truckloads is developed. The algorithm also takes into consideration the time-window constraints and waiting costs. The resulting efficiency, validated by computational tests on random problems, is due to a column-generation scheme that exploits the special structure of the problem to solve the linear-programming relaxation problems that arise at the nodes.
The Inhomogeneous Kinematic Wave Traffic Flow Model as a Resonant Nonlinear System
Authors: Jin W.-L. , Zhang H. M.
Published: December 2003

The kinematic wave traffic flow model for an inhomogeneous road is studied as a resonant nonlinear system, where an additional conservation law is introduced to model time-invariant road inhomogeneities such as changes in grades or number of lanes. This resonant system has two families of waves, one of which is a standing wave originated at the inhomogeneity. The nature of these waves are examined and their time-space structures are studied under Riemann initial conditions and proper entropy conditions. Moreover, the system is solved numerically with Godunov's method, and the solutions are found to be consistent with those of Daganzo (1995) and Lebacque (1996) for the same initial conditions. Finally, the numerical approximation is applied to model traffic flow on a ring road with a bottleneck and the results conform to expectations.
Estimating Regional Air Quality Vehicle Emission Inventories: Constructing Robust Driving Cycles
Authors: Lin Jie , Niemeier Debbie A.
Published: December 2003

Mobile emission inventories are constructed by multiplying a pollutant emission factor by a travel activity (e.g., number of trips, vehicle miles traveled, etc.). To create emission rates, vehicles are tested on dynamometers using driving cycles, or speed-time traces. The process currently used to create the driving cycles is deterministic. However, if we examine the data and data collection techniques closely, it is clear that an observed speed, v(t), represents one of the many possible values that true speed, V(t), may take on at a given time t. With an ordered set of random variables {V(t)} and associated probability distributions, driving cycles should be defined by a stochastic process. In this study, we propose a new approach for constructing driving cycles using Markov process theory. The new approach not only provides an important statistical foundation for drive cycle estimation, it also overcomes several key limitations of the current driving cycle construction methodologies. For example, we use a maximum likelihood estimation (MLE) partitioning algorithm that enables us to associate a segment with a specific modal operating condition, (e.g., cruise, idle, acceleration, or deceleration), which, in turn, preserves finely resolved driving variability. We apply the new method to the data used to construct EPA's new regulatory facility-specific driving cycles. Comparisons with these cycles indicate relatively similar global results (e.g., average speeds) under uncongested conditions. However, the new cycles tend to contain a higher frequency of small scale acceleration and deceleration modal events than are represented in the EPA cycles. For congested conditions, in addition to greater frequencies of acceleration and deceleration modal events, the new cycles tend to have higher speeds and harder accelerations. Overall, the improvements in the new method represent significant advances in the development of stochastic driving cycle construction methods.
Applications of Operations Research in the Air Transport Industry
Authors: Barnhart Cynthia , Belobaba Peter , Odoni Amedeo R.
Published: December 2003

This paper presents an overview of several important areas of operations research applications in the air transport industry. Specific areas covered are: the various stages of aircraft and crew schedule planning; revenue management, including overbooking and leg-based and network-based seat inventory management; and the planning and operations of aviation infrastructure (airports and air traffic management). For each of these areas, the paper provides a historical perspective on OR contributions, as well as a brief summary of the state of the art. It also identifies some of the main challenges for future research.
How to Obtain Uniformity of Occlusal Detail
Authors: Wilson Nairn HF , Wilson Margaret
Published: December 2003

At a recent Primary Dental Care Editorial Board meeting it was suggested that a series of short articles providing practical advice on clinical procedures might well be appreciated by our readers. This, then, is an invitation to our readers to submit material of this type, for publication. The text may be kept brief by the use of illustrations. The following example is the type of communication that we have in mind, but any information of a practical nature about the use of dental products would be carefully considered. We are grateful to the publishers of Fenestra (3M Dental Products) and the authors for permission to republish this piece first published in 1999.
Advances in Dental Imaging
Authors: Brown Jackie E
Published: December 2003

The number of dental radiographs taken in the UK has steadily increased over the past 20 years—recently estimating around 18 million taken in the general dental services alone, and dental radiographs now account for nearly 25% of all medical radiographic exposures.1

Radiographs remain our most useful diagnostic aid. Their strength is in demonstrating hard tissue pathology, which makes radiographs particularly effective in the maxillofacial region. Although well accepted in this capacity, there remain a number of limitations and drawbacks to conventional radiographs which recent developments have begun to overcome. There have been improvements in the scope and capabilities of dental imaging equipment. There has also been a continuing effort to reduce radiation-induced harm by limiting our exposure to it. This has been possible both through the introduction of new methods and protocols for reducing individual radiation exposures and by the creation of guidelines for selecting radiographs more effectively and thereby reducing the total number of radiographs taken.
Is the Current Access to Health Information Helping or Hindering Effective Decision-making for Dentists and Patients? Guidelines for Dental Practice
Authors: Best Helen A , Bedi Raman
Published: December 2003

With the introduction of the Internet there has been a growth both in the quantity and accessibility of information to the public concerning health issues. This improved availability of information does not always lead to a more informed public since there is no quality control of information but it can lead to a public that takes a more active role in their own health and thus is involved in shared decision-making.

In order to develop a more informed public in the future, systems for quality control of information have been addressed. These systems can range from the present state of uncontrolled information (no quality control) to full-centralised control (censored information). Between these extremes lie two, more appropriate, decentralised filtering approaches—'upstream filtering’ (where third parties set quality criteria and evaluate information) and ‘down-stream filtering’ (where data are rated, labelled and weighted according to consumers’ criteria). These systems of filtering are discussed along with recommendations for those using the Internet as a source of information. The paper also documents reliable sources of information for the public, highlights the current concepts of shared decision-making, and provides some guidelines for developing an effective decision-making strategy.
Suicide in the Medically Ill
Authors: Hughes Douglas , Kleespies Phillip
Published: December 2003

“The undiscover'd country, from whose bourn No traveler returns puzzles the will, And makes us rather bear those ills we have Than fly to others that we know not of?” (Hamlet III, i)
Activity Involvement Among Suicidal and Nonsuicidal High‐Risk and Typical Adolescents
Authors: Mazza James J. , Eggert Leona L.
Published: December 2003

The purpose of this study was to compare weekly activities among four groups of randomly selected high‐risk and typical high school students: (1) potential dropouts at suicide risk, (2) typical youth at suicide risk, (3) potential dropouts not at suicide risk, and (4) typical youth not at suicide risk. Of the 1,286 participants, 39.4% of the high‐risk and 30.1% of typical high school students screened in at suicide risk. Weekly activity comparisons across the four groups showed that suicide‐risk adolescents, regardless of potential dropout status, engaged in more solitary activities on weekdays and weekends than did their nonsuicide risk peers. High‐risk potential dropout youth engaged in less homework and more social activities during weekdays and weekends than did the typical high school students. These results provide important insight into the weekly activity involvement of at‐risk youth while helping to gain a better understanding of suicide‐risk adolescents. Implications of these findings are discussed for identifying youth at risk for suicidal behavior and for prevention programming.
Stressful Life Events and Impulsiveness in Failed Suicide
Authors: Weyrauch Karl F. , Roy‐Byrne Peter , Katon Wayne , Wilson Larry
Published: December 2003

The relationship of recent stressful life events with impulsiveness in triggering suicide attempts and how impulsiveness changes from one suicide attempt to another is unclear. This study used structured‐interview tools and standardized measurements to examine the relationship between life stress and impulsiveness in a sample of patients who required hospitalization for a medically serious suicide attempt. After controlling for potentially confounding variables, the number of disrupted interpersonal relationships in the preceding year was a significant predictor of the impulsiveness of the suicide attempt, with three or more losses (but not other life stresses) associated with less impulsive attempts (T = 2.4, p = .02). Female gender (T = −1.98, p = .05) and lifetime DMS‐III‐R diagnoses (T = −2.45, p = .02) were significantly associated with more impulsive attempts. In 55 patients with at least two suicide attempts, impulsiveness, lethal intent, and communication of intent were significantly greater for the present compared to the prior attempt (p = 0.000). Certain stressful life events, gender, and total lifetime DSM‐III‐R diagnoses are associated with impulsiveness of failed suicide attempts; yet, impulsiveness is not necessarily consistent from one suicide attempt to another. This evidence supports and amplifies a stress‐diathesis model of suicide behavior. Accordingly, efforts to increase personal resilience in individuals who have “failed suicide” may be more effective at preventing suicide morbidity than simple stress‐reduction measures alone.
Attitudes Toward Suicide Prevention in Front‐Line Health Staff
Authors: Herron Jane , Ticehurst Henry , Appleby Louis , Perry Amanda , Cordingley Lis
Published: December 2003

A questionnaire assessing attitudes toward suicide prevention was constructed and shown to have satisfactory reliability and internal consistency. The determinants and distribution of these attitudes were investigated in four groups of health professionals who are in contact with suicidal patients: general practitioners, accident and emergency nurses, psychiatrists in training, and community psychiatric nurses. Attitudes toward suicide prevention were shown to differ significantly between professional groups. More positive attitudes were associated with mental health professionals, working in the community, and previous training in suicide risk assessment. Negative attitudes should be assessed and targeted in training designed to improve the management of suicide risk.
The Influence of Geographic Mobility on Nearly Lethal Suicide Attempts
Authors: Potter Lloyd B. , Kresnow Marcie‐jo , Powell Kenneth E. , Simon Thomas R. , Mercy James A. , Lee Roberta K. , Frankowski Ralph F. , Swann Alan C. , Bayer Timothy , O'Carroll Patrick W.
Published: December 2003

Teenagers and young adults are very mobile and mobility has been identified as a potential risk factor for suicidal behavior. We conducted a population‐based, case‐control study of nearly lethal suicide attempts with 153 cases and 513 controls. Study participants were asked about changing residence over the past 12 months. Results indicate that moving in the past 12 months is positively associated with a nearly lethal suicide attempt (adjusted odds ratio of 2.1, with 95% confidence interval of 1.4–3.3), as are specific characteristics of the move (e.g., frequency, recency, distance, and difficulty staying in touch). These findings confirm and extend prior ecologic research by demonstrating a relationship, at the individual level, between the geographic mobility of adolescents and young adults and nearly lethal suicide attempts.
Help‐Seeking Behavior Prior to Nearly Lethal Suicide Attempts
Authors: Barnes Lauren Seymour , Ikeda Robin M. , Kresnow Marcie‐jo
Published: December 2003

The association between help‐seeking and nearly lethal suicide attempts was evaluated using data from a population‐based, case‐control study of 153 13‐ to 34‐year‐old suicide attempt case‐patients treated at emergency departments in Houston, Texas, and a random sample of 513 control‐subjects. Measures of help‐seeking included whether the participant sought help for health/emotional problems in the past month, type of consultant contacted, and whether suicide was discussed during the interaction. Overall, friends/family were consulted most frequently (48%). After controlling for potential confounders, case‐patients were less likely than control‐subjects to seek help from any consultant (OR = 0.5, 95% CI = 0.3–0.8) or a professional (e.g., physician, counselor) consultant (OR = 0.5, 95% CI = 0.29–0.8). Among those who sought help, case‐patients were more likely than to discuss suicide (OR = 2.6, 95% CI = 1.2–5.4), particularly with professionals (OR = 11.8, 95% CI = 3.2–43.2). Our findings suggest that efforts to better understand the role of help‐seeking in suicide prevention, including help sought from family and friends, deserves further attention.
Some question of crystallography I´d like to see answered
Authors: Baake M.
Published: December 2003

Some open problems of mathematical and theoretical crystallography are discussed which, to my opinion, are more important to crystallography than commonly accepted.
Crystal structures of hydrofluorocarbons from powder X-ray diffraction data: HFC-134a and HFC-152a
Authors: Brunelli M. , Fitch A. N.
Published: December 2003

High-resolution powder X-ray diffraction measurements have been used to determine the low-temperature crystal structures of the hydrofluorocarbons 1,1,1,2-tetrafluoroethane (HFC-134a) and 1,2-difluoroethane (HFC-152a). Below their melting points both compounds form body-centred-cubic orientationally-disordered phases with a = 5.7606(2) Å for HFC-134a and a = 5.5433(1) Å for HFC-152a, at 120 K. These transform to ordered structures on cooling, which were solved by autoindexing, intensity extraction and direct methods with the EXPO program, and refined via the Rietveld method. HCF-134a is monoclinic, space group P21/c, a = 8.7569(4) Å, b = 9.3523(1) Å, c = 9.0784(4) Å , β = 106.479(5)°, at 80 K, Z = 8. HFC-152a is monoclinic, space group Pc, a = 8.6417(2) Å, b = 7.6748(1) Å, c = 7.9123(2) Å, β= 113.367(1)º, at 90 K, Z = 6. The packing of the molecules in the low-temperature phases is influenced by the formation of weak C-H···F interactions.
Arylisocyanide derivatives of iron(0): crystal and molecular structures of Fe(CO)2[P(OPh)3]2(CNR) (R = phenyl, para-tolyl, mesityl)
Authors: Cromhout N. L. , Gallagher J. F. , Lough A. J. , Manning A. R.
Published: December 2003

The iron(0) isocyanide derivatives Fe(CO)2[P(OPh)3]2(CNR), where R = phenyl, para-tolyl and mesityl, respectively, are obtained upon photolysis of Fe(CO)3[P(OPh)3]2 and reaction of the resulting photoproduct, HFe(CO)2[P(OPh)3][(PhO)2P(o-OC6H4)], with CNR. All three molecular structures possess a similar trigonal bipyramidal geometry about the iron metal core, with trans apical phosphite ligands and a trigonal planar arrangement of CO and isocyanide ligands. The phenyl isocyanide complex crystallises with two molecules per asymmetric unit (in P21/a) comprising one ordered molecule with a bent isocyanide ligand C=N-CPh 163.5(3)° and a second molecule which is disordered with two components of equal site occupancy. The para-tolyl and mesityl isocyanide derivatives (both in C2/c) have two-fold crystallographic symmetry, with the iron atom and the isocyanide ligands residing on the two-fold axes.
Form and folding of pentameric human serum Amyloid P component
Authors: Janner A.
Published: December 2003

The molecular prismatic forms which enclose the tertiary and the quaternary structure of the human serum Amyloid P component show remarkable ratios expressible in terms of the golden mean. A scale-rotation crystallographic point group, leaving these forms invariant, allows to explain these golden mean proportions and to assign integer indices to the vertices of the molecular forms. Cα
-positions at form-confined folding points are identified and discussed on the basis of scale-rotations relating a number of corresponding ideal positions indexed by rational numbers.
Structure and transport properties of the R2Co2Al compounds (R=Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Y)
Authors: Pani M. , Merlo F. , Fornasini M. L.
Published: December 2003

The new R2Co2Al compounds (R=Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Y), studied by single crystal and powder X-ray diffraction, crystallize with the W2CoB2 structure type. Pr2Co2Al is dimorphic, showing also its own monoclinic structure (a=9.595 Å, b=5.602 Å, c=7.753 Å, β=103.89°), which is closely related to the W2CoB2 type. Both structures are based on different packing of chains of cobalt-centred double trigonal prisms formed by rare earth and aluminum atoms. The electrical resistivity, measured in the 13-300K temperature range for all phases (save Y2Co2Al), always shows a transition point at temperatures going from 14K for Tm2Co2Al to 94K for Tb2Co2Al. As already found for Gd2Co2Al, these points should correspond to an order-disorder magnetic transition, and the deviations from de Gennes scaling indicate the influence of both the crystalline electric field and the strong coupling between 4f and conduction electrons.
'Size-effect'-like distortions in quasicrystalline structures
Authors: Welberry T. R. , Honal M.
Published: December 2003

We show in this paper that by applying size-effect distortions to a perfect Penrose tiling, on the basis that rhomb-edges which connect different types of vertices assume different lengths, we can obtain a diffraction pattern which shows remarkable similarity to the zero-level (h5=0) section observed in decagonal Al71Co13Ni16. In particular a central clearly delineated decagon is observed, on the inside of which there is reduced intensity, and on the outside of which there is enhanced intensity. Such a transfer of intensity is characteristic of size-effect distortions in crystals but for these systems it is necessary to have disorder involving (at least) two types of atoms. In the present case the effect is observed with all vertices occupied by a single scatterer and the system remains topologically equivalent to the Penrose pattern with long range quasicrystallinity.
Teaching crystallography through an intensive course
Authors: Blake A. J. , Clegg W. , Howard J. A. K. , Main P. , Parsons S. , Watkin D. J. , Wilson C.
Published: December 2003

This contribution describes how an intensive biennial residential course has been developed to teach crystallography and structure determination.
Crystallographic software for the new generation
Authors: Watkin D. , Cooper R. , Prout C. K.
Published: December 2003

We see the current generation of area detector diffractometers as the heralds of a crystallographic revival, launching the renewal and revitalisation of the subject. Coupling these machines to appropriate software will enable chemists to undertake some of their own analyses, releasing structure analysts and crystallographers from the burden of routine tasks. Their skills can then be turned to the innumerable unsolved problems that can be called 'crystallographic' in the widest sense. CRYSTALS is a software suite that offers help and support to beginners, and still retains a rich wealth of crystallographic functionality.
“4 E’s” Ways That Clinicians Can Reduce Low-Value Care on Medical Wards
Authors: Silverstein William K. , Leis Jerome A. , Moriates Christopher
Published: January 2024

This JAMA Network Insight demonstrates examples of how clinicians can implement stepwise changes to reduce unnecessary patient harms, using the 4 E’s.
Sodium-Glucose Cotransporter 2 Inhibitors and Nephrolithiasis Risk in Patients With Type 2 Diabetes
Authors: Paik Julie M. , Tesfaye Helen , Curhan Gary C. , Zakoul Heidi , Wexler Deborah J. , Patorno Elisabetta
Published: January 2024

Importance

Type 2 diabetes (T2D) is associated with an increased risk of kidney stones. Sodium-glucose cotransporter 2 inhibitors (SGLT2is) might lower the risk of nephrolithiasis by altering urine composition. However, no studies have investigated the association between SGLT2i use and nephrolithiasis risk in patients receiving routine care in the US.

Objective

To investigate the association between SGLT2i use and nephrolithiasis risk in clinical practice.

Design, Setting, and Participants

This new-user, active comparator cohort study used data from commercially insured adults (aged ≥18 years) with T2D who initiated treatment with SGLT2is, glucagon-like peptide 1 receptor agonists (GLP-1RAs), or dipeptidyl peptidase 4 inhibitors (DPP4is) between April 1, 2013, and December 31, 2020. The data were analyzed from July 2021 through June 2023.

Exposure

New initiation of an SGLT2i, GLP-1RA, or DPP4i.

Main Outcomes and Measures

The primary outcome was nephrolithiasis diagnosed by International Classification of Diseases codes in the inpatient or outpatient setting. New SGLT2i users were 1:1 propensity score matched to new users of a GLP-1RA or DPP4i in pairwise comparisons. Incidence rates, rate differences (RDs), and estimated hazard ratios (HRs) with 95% CIs were calculated.

Results

After 1:1 propensity score matching, a total of 716 406 adults with T2D (358 203 pairs) initiating an SGLT2i or a GLP-1RA (mean [SD] age, 61.4 [9.7] years for both groups; 51.4% vs 51.2% female; 48.6% vs 48.5% male) and 662 056 adults (331 028 pairs) initiating an SGLT2i or a DPP4i (mean [SD] age, 61.8 [9.3] vs 61.7 [10.1] years; 47.4% vs 47.3% female; 52.6% vs 52.7% male) were included. Over a median follow-up of 192 (IQR, 88-409) days, the risk of nephrolithiasis was lower in patients initiating an SGLT2i than among those initiating a GLP-1RA (14.9 vs 21.3 events per 1000 person-years; HR, 0.69 [95% CI, 0.67-0.72]; RD, −6.4 [95% CI, −7.1 to −5.7]) or a DPP4i (14.6 vs 19.9 events per 1000 person-years; HR, 0.74 [95% CI, 0.71-0.77]; RD, −5.3 [95% CI, −6.0 to −4.6]). The association between SGLT2i use and nephrolithiasis risk was similar by sex, race and ethnicity, history of chronic kidney disease, and obesity. The magnitude of the risk reduction with SGLT2i use was larger among adults aged younger than 70 years vs aged 70 years or older (HR, 0.85 [95% CI, 0.79-0.91]; RD, −3.46 [95% CI, −4.87 to −2.05] per 1000 person-years; P for interaction <.001).

Conclusions and Relevance

These findings suggest that in adults with T2D, SGLT2i use may lower the risk of nephrolithiasis compared with GLP-1RAs or DPP4is and could help to inform decision-making when prescribing glucose-lowering agents for patients who may be at risk for developing nephrolithiasis.
What Parents Need to Know About Penicillin Allergy Labels
Authors: Fender Alexander W. , Thompson Jennifer L. , Thompson Lindsay A.
Published: January 2024

This JAMA Pediatrics Patient Page describes why it is important for children to see their pediatrician for any concern about a reaction to penicillin before a child is considered to have a penicillin allergy.
Substance Use, Suicidal Thoughts, and Psychiatric Comorbidities Among High School Students
Authors: Tervo-Clemmens Brenden , Gilman Jodi M. , Evins A. Eden , Bentley Kate H. , Nock Matthew K. , Smoller Jordan W. , Schuster Randi M.
Published: January 2024

This cross-sectional study evaluates the dose-dependent association between alcohol, cannabis, and nicotine use and psychiatric symptoms among participants in the Substance Use and Risk Factor Survey and the Youth Risk Behavior Survey.
Harmony in chaos: understanding cancer through the lenses of developmental biology
Authors: Van Lent Jonas , Baggiolini Arianna
Published: January 2024

When we think about cancer, the link to development might not immediately spring to mind. Yet, many foundational concepts in cancer biology trace their roots back to developmental processes. Several defining traits of cancer were indeed initially observed and studied within developing embryos. As our comprehension of embryonic mechanisms deepens, it not only illuminates how and why cancer cells hijack these processes but also spearheads the emergence of innovative technologies for modeling and comprehending tumor biology. Among these technologies are stem cell‐based models, made feasible through our grasp of fundamental mechanisms related to embryonic development. The intersection between cancer and stem cell research is evolving into a tangible synergy that extends beyond the concepts of cancer stem cells and cell‐of‐origin, offering novel tools to unravel the mechanisms of cancer initiation and progression.
Unveiling the Pivotal Parameters for Advancing High Energy Density in Lithium‐Sulfur Batteries: A Comprehensive Review
Authors: Fei Yue , Li Ge
Published: January 2024

The lithium‐sulfur (Li‐S) battery stands as a strong contender for the next‐generation energy storage system, characterized by abundant sulfur resources, environmental sustainability, and high specific capacity. However, its energy density remains constrained by factors such as low sulfur loading and fraction in the cathode, excessive electrolyte, and an excess of anode. These mild conditions significantly limit the energy density of Li‐S batteries, making them less competitive. To achieve higher energy density, harsh operation conditions are necessary, but these remain challenging to implement, even in a lab‐scale production. In this comprehensive review, the emphasis will be on recent advancements in Li‐S batteries, specifically in the realm of designing high sulfur loading, high sulfur fraction, lean electrolyte, and low limited negative electrode Li‐S batteries. A visualizable model that illustrates the relationship between cell energy density and various cell parameters, underscoring the importance of exploring Li‐S batteries under extreme operating conditions for further development is provided. Furthermore, it will discussed the possibilities of achieving even higher energy density in Li‐S batteries and the challenges that need to be addressed to make them practical for real‐world applications.
Coumarin‐Based Light‐Responsive Composite Nanochannel Membranes for Precise Controlled Release of Pesticides
Authors: Gong Jue‐Ying , Zhou Xing‐Long , Faraj Yousef , Zou Lin‐Bing , Zhou Chang‐Hai , Xie Rui , Wang Wei , Liu Zhuang , Pan Da‐Wei , Ju Xiao‐Jie , Chu Liang‐Yin
Published: January 2024

The precise, controllable, and safe application of pesticides can effectively reduce pesticide consumption and minimize chemical pollution at the source. Here, a light‐responsive controlled‐release system with flexible control, precise release, easy recovery, and suitability for future pesticide application in aquatic environments is proposed. The system precisely controls the release of pesticides through a light‐responsive composite nanochannel membrane (CTC@SNM/PET) with reactive coumarin derivatives (CTC) as gating molecules. The prepared nanochannel membrane has an ultrathin thickness of 67.5 nm and well‐ordered vertical nanochannels with a uniform size of 1.9 nm, providing a prerequisite for precise molecular gating and high permeability for mass transport. CTC monomers can realize cycloaddition/cyclocracking and nanochannel closing/opening to control the release of pesticides by controlling 365/254 nm ultraviolet light irradiation. As a proof of concept, the light‐responsive controlled‐release system based on CTC@MSF/PET against Saprolegnia parasitica achieves an inhibition rate of more than 95% and reduces pesticide residues by 56.5% compared to the control group. The proposed membrane system has great application potential to easily enable remote, quantitative, timed, and positioned pesticide application, thereby reducing pesticide residues and providing a prospective approach to reducing environmental and human risks.
Breaking‐Down Tumoral Physical Barrier by Remotely Unwrapping Metal‐Polyphenol‐Packaged Hyaluronidase for Optimizing Photothermal/Photodynamic Therapy‐Induced Immune Response
Authors: Sun Quanwei , Li Yunlong , Shen Wei , Shang Wencui , xu Yujing , Yang Jinming , Chen Jie , Gao Wenheng , Wu Qinghua , Xu Fan , Yang Ye , Yin Dengke
Published: January 2024

The therapy of solid tumors is often hindered by the compact and rigid tumoral extracellular matrix (TECM). Precise reduction of TECM by hyaluronidase (HAase) in combination with nanotechnology is promising for solid tumor therapeutics, yet remains an enormous challenge. Inspired by the treatment of iron poisoning, here a remotely unwrapping strategy is proposed of metal‐polyphenol‐packaged HAase (named PPFH) by sequentially injecting PPFH and a clinically used iron‐chelator deferoxamine (DFO). The in situ dynamic disassembly of PPFH can be triggered by the intravenously injected DFO, resulting in the release, reactivation, and deep penetration of encapsulated HAase inside tumors. Such a cost‐effective HAase delivery strategy memorably improves the subsequent photothermal and photodynamic therapy (PTT/PDT)‐induced intratumoral infiltration of cytotoxic T lymphocyte cells and the cross‐talk between tumor and tumor‐draining lymph nodes (TDLN), thereby decreasing the immunosuppression and optimizing tumoricidal immune response that can efficiently protect mice from tumor growth, metastasis, and recurrence in multiple mouse cancer models. Overall, this work presents a proof‐of‐concept of the dynamic disassembly of metal‐polyphenol nanoparticles for extracellular drug delivery as well as the modulation of TECM and immunosuppressive tumor microenvironment.
Advanced Effect of the Substitution of Zn2+ on the Solid‐State Synthesis of Red Phosphor, High Temperature Phase NaMgPO4:Eu2+
Authors: Du Yuze , Seto Takatoshi , Liu Wenjing , Wang Yuhua , Ma Xiongbo
Published: January 2024

It is known that high‐temperature phase (olivine structure) of NaMgPO4:Eu2+ (NMP:Eu2+) is a precious oxide phosphor suitable for LED devices, emitting red at 625 nm under blue excitation. However, mainly due to the stable glaserite structure in the wide range of low temperature, pure olivine‐phase NMP:Eu2+ is obtained only by using melt‐quenching and arc‐imaging furnace so far, which is inconvenient for the purpose of mass‐production or industry. Generally, a traditional solid‐state method is simpler and pollution‐free, which is more favorable in phosphor‐industry. Here, it is found that when quite small amount of Zn2+ is substituted for NMP:Eu2+ in solid‐state method, the purity of olivine phase is much improved and the luminescence intensity is significantly improved. For the Na(Mg,Zn)PO4:Eu2+ having new composition, crystal structure, optical properties, and color properties are investigated. The phase transition temperature before and after doping with Zn2+ are calculated by combining TG/DSC experimental measurements and first‐principles calculations. In addition, other characteristics related to the phosphor, such as structure, morphology, luminescence lifetime, thermal quenching properties, and quantum efficiency, are also studied in detail. Finally, it is demonstrated that this phosphor can be utilized in various applications through the manufacturing of LED devices, fluorescent pigments, and plant growth.
Synthetic Fourier Domain Optical Coherence Tomography
Authors: Alexandrov Sergey , McAuley Ryan , Dey Rajib , Arangath Anand , Zhou Yi , Nolan Andrew , Owens Peter , Leahy Martin
Published: January 2024

A novel approach for image formation in optical coherence tomography (OCT) and microscopy is presented. The depth resolution of OCT, including recently developed nanosensitive OCT (nsOCT), is limited by the spectral bandwidth of the light source used for illumination. The proposed approach, synthetic OCT (synOCT), permits label‐free, depth‐resolved quantitative visualization of the subwavelength‐sized structures with nanosensitivity. Using synOCT it is possible to estimate the contribution of axial Fourier components of an object's structure in image formation at each small volume within the image. The size of such areas can be smaller than the resolution limit of the imaging system that provides potential for super‐resolution imaging. Visualization of the subwavelength periodic structures and quantitative visualization of the subwavelength internal structures of highly scattering biological samples, within voxels smaller than resolution limit of the imaging system, are demonstrated. In contrast to nsOCT, the trade‐off between spectral and spatial resolution is removed which results in dramatic improvement of both spectral and spatial resolution in synOCT relative to nsOCT.
Adjusting Electronic Properties of Janus SHfAZ2 (A═Si,Ge; Z═N, P, As) via Strain Engineering and an Electric Field
Authors: Gao Zhen , He Yao , Xiong Kai
Published: January 2024

In this work, novel monolayers of 2D Janus SHfAZ2 (A═Si, Ge; Z═N, P, As) materials are introduced. These Janus structures are primarily investigated for their ability to exhibit adjustable electronic properties when subjected to biaxial strain and an applied electric field. At equilibrium, the four structures in the Janus SHfAZ2 monolayers all display indirect bandgap semiconductor properties, with the exception of the SHfGeN2 monolayer, which exhibits direct bandgap semiconductor properties. Under the influence of biaxial strain, the study observes that the electronic properties of all SHfAZ2 monolayers can be adjusted, transitioning from semiconductor to metallic properties when subjected to compressive strain. However, the SHfSiP2, SHfGeP2, and SHfGeAs2 monolayers show limited sensitivity to an applied electric field, with their electronic properties being modifiable solely under the influence of applied biaxial strain. In contrast, both the SHfSiAs2 and SHfGeN2 monolayers demonstrate the ability to modulate their electronic properties from semiconductors to metals when subjected to both biaxial strain and an applied electric field. Finally, the carrier mobility of these five structures is calculated. The outcomes of the research provide a solid theoretical foundation for the potential utilization of 2D Janus SHfAZ2 monolayers in electronic devices.
Stateful Logic Operation of Gated Silicon Diodes for In‐Memory Computing
Authors: Son Jaemin , Jeon Juhee , Cho Kyoungah , Kim Sangsig
Published: January 2024

In‐memory computing significantly reduces workload and energy cost of data access in the traditional von Neumann computing architecture. Using various memristors, stateful logic is developed to realize in‐memory computing. However, memristors have encountered critical issues in terms of device variation and reliability, and therefore, fundamental device solutions are required to realize practical stateful logic. In this study, NAND, NOR, and half‐adder stateful logic operations of gated silicon diodes with a p+–n–p–n+ structure are demonstrated to achieve in‐memory computing. Gated diodes have bistable, steep switching, and quasi‐nonvolatile memory characteristics, enabling reliable stateful logic operation. The uniformity of their device characteristics overcomes the inherent stochastic characteristics of memristors that are widely researched for stateful logic. The sequential multiread logic operation simplifies the complex state logic scheme. In particular, a nondestructive half‐adder operation can be executed in five sequential steps using six parallel diodes. Thus, the stateful logic of gated diodes can be a potential building block for in‐memory computing.
Asymmetric Atomic Tin Catalysts with Tailored p‐Orbital Electron Structure for Ultra‐Efficient Oxygen Reduction
Authors: Lin Xuanni , Zhang Xinqiang , Liu Dong , Shi Lei , Zhao Linjie , Long Yongde , Dai Liming
Published: January 2024

Atomically dispersed transition metal–nitrogen–carbon (M–N–C) catalysts guide by the d‐band center theory have been extensively studied for oxygen reduction reaction (ORR) in various energy conversion and storage processes. However, asymmetric p‐block metal single‐atom catalysts (SACs) toward ORR have rarely been reported, and the origin of their catalytic activity is still unclear. Here, an asymmetric N, O coordinated Sn SAC is developed as an efficient ORR electrocatalyst. Remarkably, the optimized Sn SAC (e.g., Sn–N/O–C) exhibit outstanding ORR performance with a half‐wave potential of 0.910 V in alkaline media, outperforming most state‐of‐the‐art ORR catalysts. More importantly, the Sn–N/O–C possesses a long‐term durability in both alkaline and acidic electrolytes. Besides, Zn–air batteries based on the Sn–N/O–C cathode also show a higher energy density (254 mW cm‐2) than that of their reported M–N–C counterparts. Theoretical calculations suggest that the asymmetric N, O coordinated atomic Sn sites have a stronger binding interaction with O2 and better charge transfer ability compared with the symmetric SnN4 sites, thereby facilitating the ORR process. This work provides a nitrogen‐, oxygen‐coordinated engineering strategy for the rational design of highly active and durable carbon‐based catalysts with atomic p‐block metal sites for ORR and beyond.
Investigation of the impact of COVID‐19 on postoperative outcomes using a nationwide Japanese database of patients undergoing laparoscopic distal gastrectomy and low anterior resection for gastric cancer and rectal cancer
Authors: Akagi Tomonori , Endo Hideki , Inomata Masafumi , Shiroshita Hidefumi , Yamaguchi Shigeki , Eguchi Susumu , Wada Norihito , Kurokawa Yukinori , Seki Yosuke , Sakai Yoshiharu , Yamamoto Hiroyuki , Kakeji Yoshihiro , Kitagawa Yuko , Taketomi Akinobu , Mori Masaki
Published: January 2024

Background

The COVID‐19 outbreak made conventional medical care impossible, forcing changes in both healthcare providers and patients. In Japan, COVID‐19 infection began spreading in earnest in 2020 and exploded in 2021. There was concern that the medical impact of COVID‐19 in 2021 would differ from that in 2020. We aimed to clarify the impact of COVID‐19 on mortality and anastomotic leakage in laparoscopic surgery for gastric cancer and rectal cancer in Japan using the National Clinical Database (NCD).

Methods

We collected data from patients who underwent laparoscopic distal gastrectomy (LDG) and laparoscopic low anterior resection (LLAR) from January 2018 to December 2021 from the NCD, a web‐based surgical registration system in Japan. The number of surgical cases, monthly incidence of mortality and morbidity (anastomotic leakage), standardized mortality ratio (SMR), and standardized morbidity‐leakage ratio (SMLR [ratio of observed patients to expected patients calculated using the risk calculator established in the NCD]) were evaluated.

Results

The numbers of LDG and LLAR cases continued to decline in the first year of the pandemic in 2020 and were as low in 2021 as in 2020. Although the numbers of robot‐assisted LDG and LLAR cases increased, the growth rate was lower than the rate of increase prior to the pandemic. Mortality and anastomotic leakage, two of the most important complications, as assessed by SMR and SMLR, did not worsen during the pandemic in comparison to the pre‐pandemic period.

Conclusions

Laparoscopic surgeries were performed safely in Japan and were not affected by the COVID‐19 pandemic.