bluuebunny/crossref_metadata_2025 huggingface dataset:
Association between widespread pain and dementia, Alzheimer’s disease and stroke: a cohort study from the Framingham Heart Study
Authors: Wang Kanran , Liu Hong
Published: August 2021

Background and objective

Chronic pain may be an early indicator of cognitive decline, but previous studies have not systematically examined the population-level associations between widespread pain and adverse cognitive outcomes and stroke. This study was designed to determine the association between widespread pain, a common subtype of chronic pain, and subsequent dementia, Alzheimer’s disease dementia and stroke.

Methods

This retrospective cohort study used data from the US community-based Framingham Heart Study. Pain status was assessed at a single time point between 1990 and 1994. Widespread pain was determined based on the Framingham Heart Study pain homunculus. Dementia follow-up occurred across a median of 10 years (IQR, 6–13 years) for persons who were dementia free at baseline. Proportional hazard models examined associations between widespread pain and incident dementia, Alzheimer’s disease dementia and stroke.

Results

A total of 347 (14.1%) subjects fulfilled the criteria for widespread pain, whereas 2117 (85.9%) subjects did not. Of 188 cases of incident all-cause dementia, 128 were Alzheimer’s disease dementia. In addition, 139 patients suffered stroke during the follow-up period. After multivariate adjustment including age and sex, widespread pain was associated with 43% increase in all-cause dementia risk (HR: 1.43; 95% CI 1.06 to 1.92), 47% increase in Alzheimer’s disease dementia risk (HR: 1.47; 95% CI 1.13 to 2.20) and 29% increase in stroke risk (HR: 1.29; 95% CI 1.08 to 2.54). Comparable results were shown in the subgroup of individuals over 65 years old.

Conclusion

Widespread pain was associated with an increased incidence of all-cause dementia, Alzheimer’s disease dementia and stroke.

Trial registration number

NCT00005121.
Two new species of encrusting sponge (Porifera, family Crellidae) from eastern Canada
Authors: Goodwin Claire , Dinn Curtis , Nefedova Ekaterina , Nijhof Frauke , Murillo Francisco Javier , Nozères Claude
Published: August 2021

Two new species of Crellidae Dendy, 1922 from the east coast of Canada are described. The first is Crella (Pytheas) cutis sp. nov., a massively encrusting species of Crella (Pytheas) collected from depths of 84 to 249 m in the Gulf of St. Lawrence and on the Scotian Shelf. The second is Crellomima mehqisinpekonuta sp. nov., a thinly encrusting sponge found at diving depths in the Bay of Fundy. We also report the first records of Crellomima derma Hentschel, 1929 from outside the type locality (Barents Sea). All known species of Crellomima are reviewed based on type material.
An investigation of the $$\alpha _S$$ and heavy quark mass dependence in the MSHT20 global PDF analysis
Authors: Cridge T. , Harland-Lang L. A. , Martin A. D. , Thorne R. S.
Published: August 2021

We investigate the MSHT20 global PDF sets, demonstrating the effects of varying the strong coupling $$\alpha _S(M_Z^2)$$

α
S

(

M
Z
2

)

and the masses of the charm and bottom quarks. We determine the preferred value, and accompanying uncertainties, when we allow $$\alpha _S(M_Z^2)$$

α
S

(

M
Z
2

)

to be a free parameter in the MSHT20 global analyses of deep-inelastic and related hard scattering data, at both NLO and NNLO in QCD perturbation theory. We also study the constraints on $$\alpha _S(M_Z^2)$$

α
S

(

M
Z
2

)

which come from the individual data sets in the global fit by repeating the NNLO and NLO global analyses at various fixed values of $$\alpha _S(M_Z^2)$$

α
S

(

M
Z
2

)

, spanning the range $$\alpha _S(M_Z^2)=0.108$$

α
S

(

M
Z
2

)

=
0.108

to 0.130 in units of 0.001. We make all resulting PDFs sets available. We find that the best fit values are $$\alpha _S(M_Z^2)=0.1203\pm 0.0015$$

α
S

(

M
Z
2

)

=
0.1203
±
0.0015

and $$0.1174\pm 0.0013$$

0.1174
±
0.0013

at NLO and NNLO respectively. We investigate the relationship between the variations in $$\alpha _S(M_Z^2)$$

α
S

(

M
Z
2

)

and the uncertainties on the PDFs, and illustrate this by calculating the cross sections for key processes at the LHC. We also perform fits where we allow the heavy quark masses $$m_c$$

m
c

and $$m_b$$

m
b

to vary away from their default values and make PDF sets available in steps of $$\Delta m_c =0.05~\mathrm GeV$$

Δ

m
c

=
0.05

G
e
V

and $$\Delta m_b =0.25~\mathrm GeV$$

Δ

m
b

=
0.25

G
e
V

, using the pole mass definition of the quark masses. As for varying $$\alpha _S(M_Z^2)$$

α
S

(

M
Z
2

)

values, we present the variation in the PDFs and in the predictions. We examine the comparison to data, particularly the HERA data on charm and bottom cross sections and note that our default values are very largely compatible with best fits to data. We provide PDF sets with 3 and 4 active quark flavours, as well as the standard value of 5 flavours.
The Z lineshape challenge: ppm and keV measurements
Authors: Alcaraz Maestre Juan , Blondel Alain , Dam Mogens , Janot Patrick
Published: August 2021

The FCC-ee offers powerful opportunities for direct or indirect evidence for physics beyond the standard model, via a combination of high-precision measurements and searches for forbidden and rare processes and feebly coupled particles. A key element of FCC-ee physics program is the measurement of the Z lineshape from a total of $$5\times 10^{12}$$

5
×

10
12

Z bosons and a beam-energy calibration with relative uncertainty of $$10^{-6}$$

10

-
6

. With this exceptionally large event sample, five orders of magnitude larger than that accumulated during the whole LEP1 operation at the Z pole, the defining parameters—$$m_\mathrm{Z}$$

m
Z

, $$\Gamma _\mathrm{Z}$$

Γ
Z

, $$N_\nu $$

N
ν

, $$\sin ^2\theta _\mathrm{W}^\mathrm{eff}$$

sin
2

θ

W

eff

, $$\alpha _\mathrm{S}(m_\mathrm{Z}^2)$$

α
S

(

m

Z

2

)

, and $$\alpha _\mathrm{QED}(m^2_\mathrm{Z})$$

α
QED

(

m
Z
2

)

—can be extracted with a leap in accuracy of up to two orders of magnitude with respect to the current state of the art. The ultimate goal that experimental and theory systematic errors match the statistical accuracy (4 keV on the Z mass and width, $$3\times 10^{-6}$$

3
×

10

-
6

on $$\sin ^2\theta _\mathrm{W}^\mathrm{eff}$$

sin
2

θ

W

eff

, a relative $$3\times 10^{-5}$$

3
×

10

-
5

on $$\alpha _\mathrm{QED}$$

α
QED

, and less than 0.0001 on $$\alpha _\mathrm{S}$$

α
S

) leads to highly demanding requirements on collider operation, beam instrumentation, detector design, computing facilities, theoretical calculations, and Monte Carlo event generators. Such precise measurements also call for innovative analysis methods, which require a joint effort and understanding between theorists, experimenters, and accelerator teams.
Can classical electrodynamics predict nonlocal effects?
Authors: Heras José A. , Heras Ricardo
Published: August 2021

Classical electrodynamics is a local theory describing local interactions between charges and electromagnetic fields and therefore one would not expect that this theory could predict nonlocal effects. But this perception implicitly assumes that the electromagnetic configurations lie in simply connected regions. In this paper, we consider an electromagnetic configuration lying in a non-simply connected region, which consists of a charged particle encircling an infinitely long solenoid enclosing a uniform magnetic flux, and show that the electromagnetic angular momentum of this configuration describes a nonlocal interaction between the encircling charge outside the solenoid and the magnetic flux confined inside the solenoid. We argue that the nonlocality of this interaction is of topological nature by showing that the electromagnetic angular momentum of the configuration is proportional to a winding number. The magnitude of this electromagnetic angular momentum may be interpreted as the classical counterpart of the Aharonov–Bohm phase.
Two-level systems coupled to Graphene plasmons: A Lindblad equation approach
Authors: Antão T. V. C. , Peres N. M. R.
Published: August 2021

In this paper, we review the theory of open quantum systems and macroscopic quantum electrodynamics, providing a self-contained account of many aspects of these two theories. The former is presented in the context of a qubit coupled to a electromagnetic thermal bath, the latter is presented in the context of a quantization scheme for surface-plasmon polaritons (SPPs) in graphene based on Langevin noise currents. This includes a calculation of the dyadic Green’s function (in the electrostatic limit) for a Graphene sheet between two semi-infinite linear dielectric media, and its subsequent application to the construction of SPP creation and annihilation operators. We then bring the two fields together and discuss the entanglement of two qubits in the vicinity of a graphene sheet which supports SPPs. The two qubits communicate with each other via the emission and absorption of SPPs. We find that a Schrödinger cat state involving the two qubits can be partially protected from decoherence by taking advantage of the dissipative dynamics in graphene. A comparison is also drawn between the dynamics at zero temperature, obtained via Schrödinger’s equation, and at finite temperature, obtained using the Lindblad equation.
Abundant wave solutions of the perturbed Gerdjikov–Ivanov equation in telecommunication industry
Authors: Khater Mostafa M. A.
Published: August 2021

In this paper, the solitary wave solutions of the complex perturbed Gerdjikov–Ivanov (CPGI) equation are investigated by employing the extended simplest equation (ESE) and modified Khater (MKhat) methods. The studied equation describes the physical characterization of the optical soliton waves to mitigate internet bottlenecks with many different applications in the telecommunication industry. The evaluated solutions are explained through various sketches in two-, three-dimensional, and contour plots of their real, imaginary, and absolute values. The novelty of the obtained results is demonstrated by comparing them with the previously obtained solutions. The computational applied schemes’ performance is tested to illustrate their powerful and effective handling of many nonlinear evolutions equations.
Predictions of the Mechanical Performance of Leaf Fiber Thermoplastic Composites by FEA
Authors: AL-Oqla Faris M.
Published: August 2021

The available potential plant waste could be worthy material to strengthen polymers to make sustainable products and structural components. Therefore, modeling the natural fiber polymeric-based composites is currently required to reveal the mechanical performance of such polymeric green composites for various green products. This work numerically investigates the effect of various fiber types, fiber loading, and reinforcement conditions with different polymer matrices towards predicting the mechanical performance of such natural fiber composites. Cantilever beam and compression schemes were considered as two different mechanical loading conditions for structural applications of such composite materials. Finite element analysis was conducted to modeling the natural fiber composite materials. The interaction between the fibers and the matrices was considered as an interfacial friction force and was determined from experimental work by the pull out technique for each polymer and fiber type. Both polypropylene and polyethylene were considered as composite matrices. Olive and lemon leaf fibers were considered as reinforcements. Results have revealed that the deflection resistance of the natural fiber composites in cantilever beam was enhanced for several reinforcement conditions. The fiber reinforcement was capable of enhancing the mechanical performance of the polymers and was the best in case of 20 wt.% polypropylene/lemon composites due to better stress transfer within the composite. However, the 40 wt.% case was the worst in enhancing the mechanical performance in both cantilever beam and compression cases. The 30 wt.% of polyethylene/olive fiber was the best in reducing the deflection of the cantilever beam case. The prediction of mechanical performance of natural fiber composites via proper numerical analysis would enhance the process of selecting the appropriate polymer and fiber types. It can contribute finding the proper reinforcement conditions to enhance the mechanical performance of the natural fiber composites to expand their reliable implementations in more industrial applications.
Large Deformation Dynamic Analysis of a Cable System by a New Hamiltonian Finite Element Method
Authors: Ding Huaiping , Yin Xiaochun , Wang Qiao , Zhu Zheng H.
Published: August 2021

This paper develops a new Hamiltonian nodal position finite element method for dynamic analysis of spatial flexible cable systems with large deformation. The dynamic governing equation is derived from finite elasticity theory. Logarithmic strain is applied to construct large deformation Hamiltonian canonical equations. An efficient second-order symplectic difference algorithm is built to solve the canonical equations numerically. A large strain conical pendulum system is analyzed numerically by the proposed method, and the numerical results are compared with those retracted from the existing Hamiltonian methods and Livermore Software Technology Corporation: dynamics (LS-DYNA). The proposed method is further verified by two tethered dynamic experiments involving large displacement motion and large deformation. The comparisons and verifications demonstrate that the proposed method is of symplectic conservation, has high accuracy and has stability for calculating flexible cable system dynamics with large deformation.
Finite Deformation of Swollen pH-Sensitive Hydrogel Cylinder Under Extension and Torsion and its Poynting Effect: Analytical Solution and Numerical Verification
Authors: Niroumandi Soha , Shojaeifard Mohammad , Baghani Mostafa
Published: August 2021

According to the rise of technological interest in hydrogels, there is a growing necessity for precise mechanical and thermodynamic experimental characterizations. One of the common experimental protocols is applying combined extension-torsion loading on a cylinder. Therefore, we have proposed an analytical solution for the problem of torsion superimposed extension coupling with pH variation on a cylinder composed of the pH-sensitive hydrogel. Additionally, the Poynting effect as an inherently nonlinear phenomenon is studied for a hydrogel cylinder under extension-torsion loading. The finite deformation of a swollen cylinder is investigated using a constitutive model that captures network stretching, mixing of polymeric network and solvent, mixing of mobile ions with the solvent, and acidic groups’ dissociation. To evaluate the analytical solution accuracy, 3D finite element analysis (FEA) has been carried out for the same problem. In this regard, it is required to develop a user-defined subroutine, UHYPER, for pH-sensitive hydrogels; the developed subroutine is validated via free-swelling and constrained swelling problems. Compared to the FEA, the presented analytical solution is more interesting regarding its low computational cost. It is perceived that the computational cost of the analytic solution is much lower than the one required for FE analysis (around 1%). Thus, the proposed solution can be utilized as aneffective toolto examine each factor on the swelling behavior of hydrogels, including mechanical properties as well as loading parameters. Moreover, the developed analytical solution can be employed for calibrating material parameters. Finally, Poynting effects are examined for various axial stretches and twists, pH values, and cross-linked densities.
Further generalizations of some Hecke-type identities
Authors: Zhang Helen W. J.
Published: August 2021

Since the study by Jacobi and Hecke, Hecke-type identities have received a lot of attention. In this paper, we obtain a general transformation formula for [Formula: see text]-series. Based on this formula, we derive a new [Formula: see text]-formula in this paper, which clearly includes infinitely many [Formula: see text]-identities. Other identities of Andrews and Liu and new identities for Hecke-type series are also discussed. As applications, we utilize some of these Hecke-type identities to establish families of inequalities for several partition functions.
Penetration and uplift resistances of two interfering pipelines buried in clays
Authors: Seehavong Sorawit , Keawsawasvong Suraparb
Published: August 2021

The primary aim of this paper is to determine penetration and uplift resistances of two interfering pipelines buried in clay with a linear increase in strength. The advanced finite element limit analysis of upper and lower bound theorems is used to perform new limit analysis solutions for both penetration and uplift resistances of two interfering pipelines. The strength profiles of cohesive soils are the cases of normally consolidated clays in deep water by setting the shear strength at the ground surface to be zero and linearly increased with the depth. The twin pipelines have the same geometries and are simultaneously failed at the same magnitude of the failure uplift or bearing loads. There are three considered input parameters including the spacing between the pipes, the embedded depth of the pipes, and the unit weight of soils. All input parameters have significant influences on the penetration and uplift resistances of two interfering pipelines. Failure mechanisms of the problems are also investigated, and stability charts of the penetration and uplift resistances of two interfering pipelines are produced for practical uses in offshore geotechnical engineering.
Primary tissues dominated ground-level trunk diameter in
Sigillaria
: evidence from the Wuda Tuff, Inner Mongolia
Authors: D'Antonio Michael P. , Boyce C. Kevin , Zhou Wei-Ming , Pfefferkorn Hermann W. , Wang Jun
Published: August 2021

Arborescent lycopsid stumps are typically fossilized as casts, so that proximal anatomy is rarely available for study. This presents a roadblock for empirically reconstructing their early ontogeny, which requires knowledge of proximal tissue proportions. Here, we describe nine upright,
in situ
stump casts of
Sigillaria
from the earliest Permian Wuda Tuff, Inner Mongolia, China that preserve traces of internal anatomy. From these specimens, we interpret thin vasculature and periderm and a broad primary cortex within
c
. 50 cm of ground level in the living plant. These specimens support recent arguments that periderm production was limited in arborescent lycopsids and that the primary body reached its mature diameter close to ground level rather than distally further up the trunk.

Supplementary material
: Additional figures of specimens and data regarding where measurements were made are available at
https://doi.org/10.6084/m9.figshare.c.5558620
Reparo: A Fast RAID Recovery Scheme for Ultra-large SSDs
Authors: Hong Duwon , Ha Keonsoo , Ko Minseok , Chun Myoungjun , Kim Yoona , Lee Sungjin , Kim Jihong
Published: August 2021

A recent ultra-large SSD (e.g., a 32-TB SSD) provides many benefits in building cost-efficient enterprise storage systems. Owing to its large capacity, however, when such SSDs fail in a RAID storage system, a long rebuild overhead is inevitable for RAID reconstruction that requires a huge amount of data copies among SSDs. Motivated by modern SSD failure characteristics, we propose a new recovery scheme, called

reparo

, for a RAID storage system with ultra-large SSDs. Unlike existing RAID recovery schemes,
reparo
repairs a failed SSD at the NAND die granularity without replacing it with a new SSD, thus avoiding most of the inter-SSD data copies during a RAID recovery step. When a NAND die of an SSD fails,
reparo
exploits a multi-core processor of the SSD controller in identifying failed LBAs from the failed NAND die and recovering data from the failed LBAs. Furthermore,
reparo
ensures no negative post-recovery impact on the performance and lifetime of the repaired SSD. Experimental results using 32-TB enterprise SSDs show that
reparo
can recover from a NAND die failure about 57 times faster than the existing rebuild method while little degradation on the SSD performance and lifetime is observed after recovery.
Multi-objective Optimization of Data Placement in a Storage-as-a-Service Federated Cloud
Authors: Chikhaoui Amina , Lemarchand Laurent , Boukhalfa Kamel , Boukhobza Jalil
Published: August 2021

Cloud federation enables service providers to collaborate to provide better services to customers. For cloud storage services, optimizing customer object placement for a member of a federation is a real challenge. Storage, migration, and latency costs need to be considered. These costs are contradictory in some cases. In this article, we modeled object placement as a multi-objective optimization problem. The proposed model takes into account parameters related to the local infrastructure, the federated environment, customer workloads, and their SLAs. For resolving this problem, we propose CDP-NSGAII

IR

, a Constraint Data Placement matheuristic based on NSGAII with Injection and Repair functions. The injection function aims to enhance the solutions’ quality. It consists to calculate some solutions using an exact method then inject them into the initial population of NSGAII. The repair function ensures that the solutions obey the problem constraints and so prevents from exploring large sets of unfeasible solutions. It reduces drastically the execution time of NSGAII. Experimental results show that the injection function improves the HV of NSGAII and the exact method by up to 94% and 60%, respectively, while the repair function reduces the execution time by an average of 68%.
Dialogue History Matters! Personalized Response Selection in Multi-Turn Retrieval-Based Chatbots
Authors: Li Juntao , Liu Chang , Tao Chongyang , Chan Zhangming , Zhao Dongyan , Zhang Min , Yan Rui
Published: August 2021

Existing multi-turn context-response matching methods mainly concentrate on obtaining multi-level and multi-dimension representations and better interactions between context utterances and response. However, in real-place conversation scenarios, whether a response candidate is suitable not only counts on the given dialogue context but also other backgrounds, e.g., wording habits, user-specific dialogue history content. To fill the gap between these up-to-date methods and the real-world applications, we incorporate user-specific dialogue history into the response selection and propose a personalized hybrid matching network (PHMN). Our contributions are two-fold: (1) our model extracts personalized wording behaviors from user-specific dialogue history as extra matching information; (2) we perform hybrid representation learning on context-response utterances and explicitly incorporate a customized attention mechanism to extract vital information from context-response interactions so as to improve the accuracy of matching. We evaluate our model on two large datasets with user identification, i.e., personalized Ubuntu dialogue Corpus (P-Ubuntu) and personalized Weibo dataset (P-Weibo). Experimental results confirm that our method significantly outperforms several strong models by combining personalized attention, wording behaviors, and hybrid representation learning.
GoSeed: Optimal Seeding Plan for Deduplicated Storage
Authors: Nachman Aviv , Sheinvald Sarai , Kolikant Ariel , Yadgar Gala
Published: August 2021

Deduplication decreases the physical occupancy of files in a storage volume by removing duplicate copies of data chunks, but creates data-sharing dependencies that complicate standard storage management tasks. Specifically, data migration plans must consider the dependencies between files that are remapped to new volumes and files that are not. Thus far, only greedy approaches have been suggested for constructing such plans, and it is unclear how they compare to one another and how much they can be improved.

We set to bridge this gap for
seeding
—migration in which the target volume is initially empty. We prove that even this basic instance of data migration is NP-hard in the presence of deduplication. We then present GoSeed, a formulation of seeding as an integer linear programming (ILP) problem, and three acceleration methods for applying it to real-sized storage volumes. Our experimental evaluation shows that, while the greedy approaches perform well on “easy” problem instances, the cost of their solution can be significantly higher than that of GoSeed’s solution on “hard” instances, for which they are sometimes unable to find a solution at all.
XStore
: Fast RDMA-Based Ordered Key-Value Store Using Remote Learned Cache
Authors: Wei Xingda , Chen Rong , Chen Haibo , Zang Binyu
Published: August 2021

RDMA
(
Remote Direct Memory Access
) has gained considerable interests in network-attached in-memory key-value stores. However, traversing the remote tree-based index in ordered key-value stores with RDMA becomes a critical obstacle, causing an order-of-magnitude slowdown and limited scalability due to multiple round trips. Using index cache with conventional wisdom—caching partial data and traversing them locally—usually leads to limited effect because of unavoidable capacity misses, massive random accesses, and costly cache invalidations.

We argue that the
machine learning
(ML) model is a perfect cache structure for the tree-based index, termed
learned cache
. Based on it, we design and implement
XStore
, an RDMA-based ordered key-value store with a new hybrid architecture that retains a tree-based index at the server to perform dynamic workloads (e.g., inserts) and leverages a learned cache at the client to perform static workloads (e.g., gets and scans). The key idea is to decouple ML model retraining from index updating by maintaining a layer of indirection from logical to actual positions of key-value pairs. It allows a stale learned cache to continue predicting a correct position for a lookup key.
XStore
ensures correctness using a validation mechanism with a fallback path and further uses speculative execution to minimize the cost of cache misses. Evaluations with YCSB benchmarks and production workloads show that a single
XStore
server can achieve over 80 million read-only requests per second. This number outperforms state-of-the-art RDMA-based ordered key-value stores (namely, DrTM-Tree, Cell, and eRPC+Masstree) by up to 5.9× (from 3.7×). For workloads with inserts,
XStore
still provides up to 3.5× (from 2.7×) throughput speedup, achieving 53M reqs/s. The learned cache can also reduce client-side memory usage and further provides an efficient memory-performance tradeoff, e.g., saving 99% memory at the cost of 20% peak throughput.
The racist “one drop rule” influencing science: it is time to stop teaching “race corrections” in medicine
Authors: Lujan Heidi L. , DiCarlo Stephen E.
Published: August 2021

Glomerular filtration rate (GFR) is a key index of renal function. The classic method for assessing GFR is the clearance of inulin. Several current methods using isotopic (125I-iothalamate, 51Cr-EDTA, or 99Tc-DTPA) or nonisotopic (iohexol or iothalamate) markers are available. Clinically, GFR is estimated (eGFR) from serum creatinine or cystatin C levels. Estimated GFR based on creatinine and/or cystatin are less accurate than measured GFR. The creatinine-based equations calculate higher eGFR values (suggesting better kidney function) for black individuals. This upward adjustment for all black individuals is embedded in eGFR calculations on the belief of higher serum creatinine concentrations among black individuals than among white individuals. Thus “race-corrected” eGFR has become a widely accepted and scientifically valid procedure. However, race is not a genetic or biological category. Rather, race is a social construction defined by region-specific cultural and historical ideas. Furthermore, there is no accepted scientific method for classifying people as black or white individuals. Studies typically rely on self-identification of race. However, any person in the United States with any known black ancestry is considered to be a black individual. This is known as the “one-drop rule,” meaning that a single drop of “black blood” makes anyone a black individual. It does not matter if an individual has 50%, 25%, 5%, or 0.5% African ancestry. The limited accuracy and reliability of this approach would not be allowed for any other scientific variable. Admixture and migration have produced such broad variations that race categories should not be used as experimental variables.
Effects of voluntary attendance patterns on first-year medical students’ wellness and academic performance during COVID-19
Authors: Salzman Joshua , Williamson Macy , Epsina-Rey Andrea , Kibble Jonathan , Kauffman Christine
Published: August 2021

There is increasing evidence that attendance is not a reliable predictor of academic performance, which invites the question of whether attendance may have alternative positive effects such as increased student wellness. While conducting an observational cohort study on the relationship of attendance to performance and wellness, the COVID-19 pandemic lockdown changed the ability of students to attend class. Matriculating medical students were recruited to participate at the beginning of their first year in August 2019. In-person attendance was collected prospectively until the lockdown began in March 2020. This was then correlated with performance on course final examinations and responses to two separate incidences of a survey on stress, burnout, social isolation, and loneliness. The first survey was deployed January through February 2020 (pre-COVID) and the second June 2020 (during COVID lockdown). Attendance declined across the year (76.0%–25.0%). There was a small positive correlation of attendance to performance in module 1 ( r = 0.235, P = 0.035) with none in the remaining two modules ( P = 0.870, P = 0.410). The high attenders at the time of the lockdown had no decline in their performance when attendance was no longer possible. Attendance negatively correlated with stress and loneliness but not with the remainder of the wellness metrics. There was no significant change in any of the wellness metrics between the pre-COVID and during COVID time points. While the data support the conclusion that attendance is not required to maintain performance in this population, these data suggest a small protective effect against stress and loneliness.
Research Progress on Durability of Cellulose Fiber-Reinforced Cement-Based Composites
Authors: Liu Jie , Lv Chun
Published: August 2021

The performance of cellulose fiber-reinforced cement-based composites (CFCCs) depends not only on the characteristics of the cement matrix and fibers but also on the bonding property of the matrix and fibers. The durability of cement-based composites including various properties such as impermeability, frost resistance, and carbonization resistance has an important impact on the long-term service life of the matrix structure. The presence of a large number of hydroxyl groups on the molecular chain of cellulose can promote the formation of intra- and intermolecular hydrogen bonds of cellulose. This special structure imparts the cellulose high hydrophilicity, which leads the cement hydration C-S-H gel to adhere to the surface of cellulosic fibers (CFs) and induce its growth. The cavity of CFs has good water absorption and can be used as an internal curing fiber for the continuous hydration of cement-based composites. But CFs in the Portland cement matrix tend to deteriorate under strong alkali conditions. This paper presents a review of the research on the durability of CFCCs. The methods and paths to improve the durability of CFCCs are summarized and analyzed from the perspectives of the internal curing of CFs, the deterioration of the performance of CFs in the matrix, and the use of many types of supplementary cementitious materials. Finally, the development and engineering application of CFCCs have been prospected.
Tips, Tricks, and Guides in Descemet Membrane Endothelial Keratoplasty Learning Curve
Authors: Borroni Davide , Rocha de Lossada Carlos , Parekh Mohit , Gadhvi Kunal , Bonzano Chiara , Romano Vito , Levis Hannah J. , Tzamalis Aris , Steger Bernhard , Rechichi Miguel , Rodriguez-Calvo-de-Mora Marina
Published: August 2021

Lamellar keratoplasty is fast becoming the most popular form of corneal transplantation. The adoption of Descemet membrane endothelial keratoplasty (DMEK) in the management of Fuchs endothelial dystrophy and pseudophakic bullous keratopathy is partly responsible for this shift in the paradigm of management of corneal pathology. The learning curve of DMEK, however, has been proven to be much steeper than previous endothelial keratoplasty procedures. To ease the procedure, experts have proposed multiple innovative techniques from tissue preparation to graft unfolding to aid the more novice surgeon. Here, we collate and share tips and tricks from our collective experiences to support the learning curve and outcomes in DMEK for both the novice and more experienced corneal transplant surgeons.
A Machine Learning Study on the Thermostability Prediction of (R)‐ω‐Selective Amine Transaminase from Aspergillus terreus
Authors: Jia Li-li , Sun Ting-ting , Wang Yan , Shen Yu
Published: August 2021

Artificial intelligence technologies such as machine learning have been applied to protein engineering, with unique advantages in protein structure, function prediction, catalytic activity, and other issues in recent years. Screening better mutants is still a bottleneck in protein engineering. In this paper, a new sequence‐activity relationship method was analyzed for its application in improving the thermal stability of Aspergillus terreus (R)‐ω‐selective amine transaminase. The experimental data from 6 single‐point mutated enzymes were used as a learning dataset to build models and predict the thermostability of 26 mutants. Based on digital signal processing (DSP), this method digitized the amino acid sequence of proteins by fast Fourier transform (FFT) and then established the best model applying partial least squares regression (PLSR) to screen out all possible mutants, especially those with high performance. In protein engineering, the innovative sequence activity relationship (ISAR) method can make a reasonable prediction using limited experimental data and significantly reduce the experimental cost. The half‐life (T1/2) of (R)‐ω‐transaminase was fitted with the amino acid sequence by the ISAR algorithm, resulting in an R2 of 0.8929 and a cvRMSE of 4.89. At the same time, the mutants with higher T1/2 than the existing ones were predicted, laying the groundwork for better (R)‐ω‐transaminase in the later stage. The ISAR algorithm is expected to provide a new technique for protein evolution and screening.
Immunomodulatory Effects of Canine Adipose Tissue Mesenchymal Stem Cell-Derived Extracellular Vesicles on Stimulated CD4+ T Cells Isolated from Peripheral Blood Mononuclear Cells
Authors: Teshima Takahiro , Yuchi Yunosuke , Suzuki Ryohei , Matsumoto Hirotaka , Koyama Hidekazu
Published: August 2021

Adipose tissue-derived mesenchymal stem cells (ADSCs) have anti-inflammatory and immunomodulatory characteristics. Many studies have suggested that the immunomodulation of ADSCs is largely mediated by secreted paracrine factors. Various factors are secreted from ADSCs, among which extracellular vesicles are considered to play a major role in the communication between ADSCs and target cells. Several studies have reported the function of canine ADSC-derived extracellular vesicles (cADSC-EVs), but few studies have reported the immunomodulatory effects of cADSC-EVs on immune cells. The purpose of this study was to investigate the effects of cADSC-EVs on in vitro-stimulated CD4+ T cells isolated from peripheral blood mononuclear cells (PBMCs). cADSC-EVs were isolated from cADSCs under naive conditions or primed conditions by tumor necrosis factor-α (TNFα) and interferon-γ (IFNγ). The expression levels of several microRNAs in cADSC-EVs were altered by priming with TNFα and IFNγ. Culturing PBMCs stimulated with concanavalin A in the presence of naive or primed cADSC-EVs inhibited the differentiation of PBMCs and CD4+ T cells and promoted apoptosis of PBMCs. CD4+, CD8+, and CD4+CD8+ T cells were decreased, while CD3+CD4-CD8- T cells were increased. T helper (Th) 1, Th2, Th17, and regulatory T (Treg) cells were analyzed by flow cytometry. cADSC-EVs inhibited the proliferation of Th1 and Th17 cells and enhanced Th2 and Treg cell proliferation. However, CD4+ T cells that had incorporated labeled cADSC-EVs comprised only a few percent of all cells. Therefore, these responses of stimulated CD4+ T cells may be due to not only direct effects of cADSC-EVs but also to indirect effects through interactions between cADSC-EVs and other immune cells. In conclusion, cADSC-EVs exert immunosuppressive effects on stimulated CD4+ T cells in vitro. These findings may be useful for further studies of immune diseases.
Microenvironment Influences on Human Umbilical Cord Mesenchymal Stem Cell-Based Bone Regeneration
Authors: E Lingling , Lu Rongjian , Sun Jianwei , Li Hongbo , Xu Wen , Xing Helin , Wang Xing , Cheng Tao , Zhang Shuo , Ma Xiaocao , Zhang Rong , Liu Hongchen
Published: August 2021

The microenvironment, or niche, regulates stem cell fate and improves differentiation efficiency. Human umbilical cord mesenchymal stem cells (hUC-MSCs) are ideal cell source for bone tissue engineering. However, the role of the microenvironments in hUC-MSC-based bone regeneration is not yet fully understood. This study is aimed at investigating the effects of the in vitro culture microenvironment (hUC-MSCs, nano-hydroxyapatite/collagen/poly (L-lactide) (nHAC/PLA), osteogenic media (OMD), and recombinant human bone morphogenetic protein-7 (rhBMP-7)) and the in vivo transplanted microenvironment (ectopic and orthotopic) on bone regeneration ability of hUC-MSCs. The isolated hUC-MSCs showed self-renewal potential and MSCs’ characteristics. In the in vitro two-dimensional culture microenvironment, OMD or OMD with rhBMP-7 significantly enhanced hUC-MSCs’ osteocalcin immunofluorescence staining, alkaline phosphatase, and Alizarin red staining; OMD with rhBMP-7 exhibited the highest ALP secretion and mineralized matrix formation. In the in vitro three-dimensional culture microenvironment, nHAC/PLA supported hUC-MSCs’ adhesion, proliferation, and differentiation; the microenvironment containing OMD or OMD and rhBMP-7 shortened cell proliferation progression and made osteogenic differentiation progression advance; rhBMP-7 significantly attenuated the inhibiting effect of OMD on hUC-MSCs’ proliferation and significantly enhanced the promoting effect of OMD on gene expression and protein secretion of osteogenic differentiation markers, calcium and phosphorous concentration, and mineralized matrix formation. The in vitro three-dimensional culture microenvironment containing OMD and rhBMP-7 induced hUC-MSCs to form the most new bones in ectopic or orthotopic microenvironment as proved by microcomputed tomography and hematoxylin and eosin staining, but bone formation in orthotopic microenvironment was significantly higher than that in ectopic microenvironment. The results indicated that the combination of in vitro hUC-MSCs+nHAC/PLA+OMD+rhBMP-7 microenvironment and in vivo orthotopic microenvironment provided a more optimized niche for bone regeneration of hUC-MSCs. This study elucidates that hUC-MSCs and their local microenvironment, or niche, play an important role in hUC-MSC-based bone regeneration. The endogenously produced BMP may serve an important regulatory role in the process.
iNOS Promotes the Development of Osteosarcoma via Wnt/β-Catenin Pathway
Authors: Chu Wei , Cao Lirong , Daokun Gui , Zhao Jiali
Published: August 2021

Inducible nitric oxide synthase (iNOS), accompanied with protumor and antitumor activity, has been studied in multiple cancers. However, the role of iNOS expression in osteosarcoma (OS) is far from being fully understood. In present work, iNOS levels were detected in OS tissues and cell lines. Colony formation assay, Transwell assay, and fow cytometer were used to assess proliferation, migration, invasion, and apoptosis abilities in vitro after iNOS inhibition. Western blotting determined the expressions of iNOS, MMP2, MMP9, C-MYC, Ki67, PCNA, and β-catenin. Mice transfected with OS cells were to evaluate tumor formation. IHC assay was to evaluate the expressions of iNOS and β-catenin in mice. The results showed that iNOS was upregulated in both OS tissues and cells compared with that in matched normal tissues or cells. And we found that proliferation, migration, and invasion numbers of OS cells were decreased, and apoptosis numbers of OS cells were increased after iNOS inhibition. MMP2, MMP9, C-MYC, Ki67, and PCNA levels were also reduced in OS cells treated with iNOS inhibition. Else, iNOS inhibition would suppress β-catenin expression in OS cells to regulate MMP2, MMP9, C-MYC, Ki67, and PCNA expressions. In addition, tumor formation, iNOS expression, and β-catenin expression were inhibited in mice transplanted with iNOS knockout OS cells. These results indicated that iNOS might be a potential therapeutic target for OS.
[Retracted] Dynamic Gesture Recognition Algorithm Based on 3D Convolutional Neural Network
Authors: Liu Yuting , Jiang Du , Duan Haojie , Sun Ying , Li Gongfa , Tao Bo , Yun Juntong , Liu Ying , Chen Baojia
Published: August 2021

Gesture recognition is one of the important ways of human‐computer interaction, which is mainly detected by visual technology. The temporal and spatial features are extracted by convolution of the video containing gesture. However, compared with the convolution calculation of a single image, multiframe image of dynamic gestures has more computation, more complex feature extraction, and more network parameters, which affects the recognition efficiency and real‐time performance of the model. To solve above problems, a dynamic gesture recognition model based on CBAM‐C3D is proposed. Key frame extraction technology, multimodal joint training, and network optimization with BN layer are used for making the network performance better. The experiments show that the recognition accuracy of the proposed 3D convolutional neural network combined with attention mechanism reaches 72.4% on EgoGesture dataset, which is improved greatly compared with the current main dynamic gesture recognition methods, and the effectiveness of the proposed algorithm is verified.
Immune Checkpoints: Therapeutic Targets for Pituitary Tumors
Authors: Nie Ding , Xue Yimeng , Fang Qiuyue , Cheng Jianhua , Li Bin , Wang Dawei , Li Chuzhong , Gui Songbai , Zhang Yazhuo , Zhao Peng
Published: August 2021

Pituitary tumors are the third most common intracranial tumors in adults. Treatment of refractory pituitary tumors is known to be difficult due to limited treatment options. As a promising therapeutic method, tumor immunotherapy has been applied in the treatment of many tumors, including pituitary tumors. Immune checkpoint blocking is one of the effective strategies to activate antitumor immunity. Immune checkpoints prevent tissue damage by regulating the immune response of peripheral tissues and participate in the maintenance of a normal immune environment. In the presence of a tumor, inhibition of T cell activity by tumor cells binding to immune checkpoints and their ligands is an important mechanism for tumor cells to escape immune injury. In this review, we summarize the latest findings of immune checkpoints and their potential as immunotherapeutic targets for pituitary tumors.
Novel Role of miR‐18a‐5p and Galanin in Rat Lung Ischemia Reperfusion‐Mediated Response
Authors: Xiao Kun , Song Lei , Hu Ye , He Wanxue , Hou Fei , Yan Peng , Xu Jianqiao , Wang Kaifei , Tao Yi , Li Dan , Xie Lixin
Published: August 2021

Lung ischemia reperfusion (IR) is known to occur after lung transplantation or cardiac bypass. IR leads to tissue inflammation and damage and is also associated with increased morbidity and mortality. Various receptors are known to partake in activation of the innate immune system, but the downstream mechanism of tissue damage and inflammation is yet unknown. MicroRNAs (miRNAs) are in the forefront in regulating ischemia reperfusion injury and are involved in inflammatory response. Here, we have identified by high‐throughput approach and evaluated a distinct set of miRNAs that may play a role in response to IR in rat lung tissue. The top three differentially expressed miRNAs were validated through quantitative PCRs in the IR rat lung model and an in vitro model of IR of hypoxia and reoxygenation exposed type II alveolar cells. Among the miRNAs, miR‐18a‐5p showed consistent downregulation in both the model systems on IR. Cellular and molecular analysis brought to light a crucial role of this miRNA in ischemia reperfusion. miR‐18a‐5p plays a role in IR‐mediated apoptosis and ROS production and regulates the expression of neuropeptide Galanin. It also influences the nuclear localization of transcription factor: nuclear factor‐erythroid 2‐related factor (Nrf2) which in turn may regulate the expression of the miR‐18a gene. Thus, we have not only established a rat model for lung IR and enumerated the important miRNAs involved in IR but have also extensively characterized the role of miR‐18a‐5p. This study will have important clinical and therapeutic implications for and during transplantation procedures.
Seismic Design Method of Self‐Centring‐Segment Bridge Piers with Tensile‐Type Viscoelastic Dampers
Authors: Gao Huixing , Song Yang , Yuan Wenting , Lu Hongxu , Cao Shuo
Published: August 2021

This paper aims to study the deformational behaviour of tensile‐type viscoelastic dampers under different earthquake excitation directions. A method for calculating the corresponding equivalent additional stiffness and damping of a self‐centring‐segment bridge pier is derived. Using the displacement‐based seismic design method, a design method for self‐centring‐segment bridge piers with tensile‐type viscoelastic dampers is proposed. Using the proposed method, a self‐centring‐segment bridge pier is designed. Based on dynamic analysis of the finite element model by OpenSees, the effectiveness of the proposed seismic design method is validated.
Analysis of the Control Effect and Parameter Optimisation of Urban Surface Deformation in Underground Coal Mining with Solid Backfilling
Authors: Wang Jiaqi , Zhang Jixiong , Zhang Qiang , Wu Zhongya , Zhang Qi , Wang Yunbo , Gao Difa
Published: August 2021

To solve the problems of surface deformation and destruction of buildings caused by urban mining and realise the coordinated development of mining cities, the solid backfilling method was used to extract coal resources beneath the buildings of Tangshan. Based on surface deformation monitoring data of the continuously operating reference station (CORS) system for the past 5 years, the surface deformation process caused by solid backfilling was analysed. The final results revealed a maximum surface subsidence of 66 mm in the T zone coal area and 31 mm in the F zone area. Furthermore, the surface control effects of the caving method and the solid backfilling method were compared and analysed, and it was shown that solid backfilling could meet the surface building setup requirements. Moreover, based on the probability integral method, the effects on surface deformation due to the surface length of the F zone, compression ratio, and coal pillar width were analysed, and the effects on the prediction results due to the subsidence factor, tangent of the major effective angle, and offset distance of the inflection point were studied. The results showed that the compression ratio is the main factor controlling the surface deformation and that it should be kept above 80% for solid backfilling of urban mines. The subsidence factor should be 0.82, and the tangent of the major effective angle should be 2.15 when the surface subsidence of solid backfilling is to be predicted. This paper provides a technical reference for the realisation of urban mining with solid backfilling.