Mass Number Research Articles

Investigating the impact of the universal function of the nuclear proximity potential in heavy-ion fusion cross sections

The fusion barriers and cross sections of 15 colliding systems with 320 ≤ Z 1 Z 2 ≤ 1512 are investigated in detail to understand the influence of the universal function of proximity potential formalism in the heavy-ion fusion mechanism. To realize this goal, we select three versions of the phenomenological proximity potentials, including Prox. 77, Zhang 2013, and Guo 2013, to calculate the nucleus–nucleus potential. The experimental fusion cross sections for the selected reactions are analyzed using the standard coupled-channel calculations, including couplings to the low-lying 2+ and 3− states in the target and projectile. The calculated results show that the universal functions of the Guo 2013 and Prox. 77 models provide the lowest and highest fusion barriers, respectively. In addition, it is found that the height of the fusion barriers is enhanced by increasing the mass number of the projectile from light to heavy ones. The highest sensitivity to the mass number of the projectile belongs to the results of Prox. 77. A discussion is also presented on the influence of the universal function on the radial behavior of the interaction potential in the allowed region for overlapping configurations. Our results reveal that the best fit to the experimental data of the fusion cross sections for the reactions involving light and medium nuclei is obtained using the universal function of the Zhang 2013 model. For the heavier systems, the results of the Guo 2013 model at sub-barrier energies provide a good description of the available data.

NRPS-like ATRR in Plant-Parasitic Nematodes Involved in Glycine Betaine Metabolism to Promote Parasitism.

Plant-parasitic nematodes (PPNs) are among the most serious phytopathogens and cause widespread and serious damage in major crops. In this study, using a genome mining method, we identified nonribosomal peptide synthetase (NRPS)-like enzymes in genomes of plant-parasitic nematodes, which are conserved with two consecutive reducing domains at the N-terminus (A-T-R1-R2) and homologous to fungal NRPS-like ATRR. We experimentally investigated the roles of the NRPS-like enzyme (MiATRR) in nematode (Meloidogyne incognita) parasitism. Heterologous expression of Miatrr in Saccharomyces cerevisiae can overcome the growth inhibition caused by high concentrations of glycine betaine. RT-qPCR detection shows that Miatrr is significantly upregulated at the early parasitic life stage (J2s in plants) of M. incognita. Host-derived Miatrr RNA interference (RNAi) in Arabidopsis thaliana can significantly decrease the number of galls and egg masses of M. incognita, as well as retard development and reduce the body size of the nematode. Although exogenous glycine betaine and choline have no obvious impact on the survival of free-living M. incognita J2s (pre-parasitic J2s), they impact the performance of the nematode in planta, especially in Miatrr-RNAi plants. Following application of exogenous glycine betaine and choline in the rhizosphere soil of A. thaliana, the numbers of galls and egg masses were obviously reduced by glycine betaine but increased by choline. Based on the knowledge about the function of fungal NRPS-like ATRR and the roles of glycine betaine in host plants and nematodes, we suggest that MiATRR is involved in nematode-plant interaction by acting as a glycine betaine reductase, converting glycine betaine to choline. This may be a universal strategy in plant-parasitic nematodes utilizing NRPS-like ATRR to promote their parasitism on host plants.

Development, Survival and Reproduction of Nezara viridula (Hemiptera: Pentatomidae) in Sesame Cultivars and Implications for the Management.

Sesame, an oilseed plant with multiple applications, is susceptible to infestations by the stink bug Nezara viridula (Linnaeus, 1758) (Hemiptera: Pentatomidae). This pest suctions the seeds of this plant and injects toxins into them. Possible sources of resistance on sesame cultivars are important to manage this bug. The objective of this study was to evaluate the biological aspects of N. viridula fed on three sesame cultivars aiming to select possible resistance sources for integrated pest management (IPM) programs of this stinkbug. The experimental design used randomized blocks with three treatments and four replications, each with newly emerged N. viridula nymphs fed with sesame capsules of the cultivars BRS Anahí (T1), BRS Morena (T2) and BRS Seda (T3). Two to three green sesame capsules were supplied every two days per group of ten N. viridula nymphs as one replication until the beginning of the adult stage. Adults of this stinkbug were fed in the same manner as its nymphs but with mature sesame capsules until the end of the observations. Survival during each of the five instars and of the nymph stage of N. viridula with green sesame capsules was similar between cultivars, but the duration of the nymph stage was shorter with green capsules of the BRS Morena than with those of the BRS Anahí. The oviposition period, number of egg masses and eggs per female, and the percentage of nymphs hatched were higher with mature capsules of the sesame cultivar BRS Anahí and lower with the others. Nymphs did not hatch from eggs deposited by females fed mature seed capsules of the sesame cultivar BRS Morena, which may indicate a source of resistance against this stinkbug in this cultivar. The worldwide importance of N. viridula to sesame cultivation makes these results useful for breeding programs of this plant aiming to develop genotypes resistant to this bug. In addition, the BRS Morena is a cultivar already commercially available and can be recommended in places where there is a history of incidence of N. viridula, aiming to manage the populations of this pest.

Study of Nano-Powell-Erying fluid flow past a porous stretching sheet by the effects of MHD, thermal and mass convective boundary conditions

The object of this research is to examine the combined effects of mass and thermal Biot numbers on the properties of a Powell-Erying fluid flow that is two-dimensional, constant, viscous, incompressible, and non-Newtonian. In the direction of the flow is an extending sheet encircled by a porous medium. Further consideration is given to the existence of a chemical reaction, thermophoresis, Brownian motion, and velocity lapse, among other factors. Utilizing the Powell-Erying Cauchy non-Newtonian model, the viscoelastic effect is accounted for. When establishing concentration and temperature boundary conditions, thermal and mass Biot numbers are incorporated. By utilizing graphs, one can examine the impacts of a variety of engineering parameters on concentration profiles, velocity, and temperature. This is accomplished through the implementation of numerical solutions derived via the Runge–Kutta method. By utilizing graphs, one can examine the impacts of a variety of engineering parameters on concentration profiles, velocity, and temperature. This is accomplished through the implementation of numerical solutions derived via the Runge–Kutta method. Furthermore, the Nusselt number, Skin-friction, and Sherwood number coefficients are evaluated and shown in a tabular format utilizing the same parameters. In the end, the numerical outcomes obtained from this investigation are substantiated and considered to be highly consistent with the findings that were previously documented.

Breast edema score at breast MRI: its value in prediction of molecular subtype of breast cancer and its impact on axillary LN metastasis

BackgroundSince many newly diagnosed breast cancer patients have breast MRI, the value of preoperative breast magnetic resonance imaging would improve if molecular subtypes could be consistently identified, and prognostic information provided in addition to diagnostic imaging. Breast edema may improve the ability to predict molecular subtypes and clinical and pathological outcomes in invasive breast cancer patients. The prognosis for breast cancer prognosis based on the findings of breast edema by magnetic resonance imaging will be useful in both pretreatment planning and prognosis. Breast edema on T2-weighted images and STIR was scored on a scale of 1 to 4, as follows: (a) breast edema score (BES) 1, no edema; (b) BES 2, peritumoral edema; (c) BES 3, pre pectoral edema; and (d) BES 4, subcutaneous edema (suspicious for occult inflammatory breast cancer “IBC”). Axillary lymph node status and number were also evaluated in T2 and STIR and after contrast administration. The aim of this work was to assess the role of tumour-related breast edema MRI features in distinguishing molecular subtypes of breast cancer and its effect on pathological axillary lymph nodes in patients with breast cancer.ResultsThere was a highly significant difference between BES with respect to the molecular subtypes of breast cancer, size of the mass, Ki-67 expression, LN status, and LN number (p < 0.0001, 0.045, < 0.0001, < 0.0001, and < 0.0001 respectively). However, there was no significant difference between BES and histopathological grade in studied masses, such as p-value = 0.49.ConclusionsTumour-related breast edema MRI characteristics may be useful in distinguishing molecular subtypes of breast cancer and could be used as a promising feature to improve the predictive performance of pathological axillary lymph nodes in patients with breast cancer, contributing to preoperative treatment planning and prognostic outcome.

Update of high voltage isolation control and monitoring system for HVE-400 ion implanter

HVE-400 ion implanter is special ion implantation equipment for semiconductor materials boron and phosphorus doping. The ion source and extraction deflection system are at high voltage platform, while the corresponding control system is at ground voltage position. The control signals and measurement signals of various parameters at the high-voltage end need to be transmitted between ground voltage and high voltage through optical fibers to isolate high voltage. Upgrading is carried out due to the aging of the optical fiber transmission control and monitoring system, which cannot work stably. The transformation replaces the original distributed single-point control method with an advanced distributed centralized control method, and integrates all control and monitoring functions into an industrial control computer for digital operation and display. In the computer software, two kinds of automatic calculation of ion mass number are designed. After upgrading, the implanter high-voltage platform control and monitoring system features digitalization, centralized control, high reliability, strong anti-interference, fast communication speed, and easy operation.

ALSTNet: Autoencoder fused long‐ and short‐term time‐series network for the prediction of tunnel structure

AbstractIt is crucial to predict future mechanical behaviors for the prevention of structural disasters. Especially for underground construction, the structural mechanical behaviors are affected by multiple internal and external factors due to the complex conditions. Given that the existing models fail to take into account all the factors and accurate prediction of the multiple time series simultaneously is difficult using these models, this study proposed an improved prediction model through the autoencoder fused long‐ and short‐term time‐series network driven by the mass number of monitoring data. Then, the proposed model was formalized on multiple time series of strain monitoring data. Also, the discussion analysis with a classical baseline and an ablation experiment was conducted to verify the effectiveness of the prediction model. As the results indicate, the proposed model shows obvious superiority in predicting the future mechanical behaviors of structures. As a case study, the presented model was applied to the Nanjing Dinghuaimen tunnel to predict the stain variation on a different time scale in the future.

Contrasting intra-urban variability of ultrafine particle number and fine particle mass concentrations in Dhaka, Bangladesh, and Pittsburgh, USA

In this study, we investigated the intra-urban variability of fine particle mass (PM2.5) and ultrafine particle number concentration (PNC) in Dhaka (Bangladesh), and Pittsburgh (USA), two cities with vastly different pollution sources and levels. We collected measurements of PNC and PM2.5 at a wide range of sites spanning a variety of urban land use attributes (35 sites in Dhaka and 30 sites in Pittsburgh). We found that PNC levels exhibited a 3-4-fold variability between sites in each city, ranging from 20,000–100,000 # cm−3 in Dhaka and 7,000–28,000 # cm−3 in Pittsburgh. PM2.5 levels varied within 50% of the urban background level, ranging from 80 to 110 μg m−3 in Dhaka and 6–12 μg m−3 in Pittsburgh. We observed a moderate level of spatial correlation between PNC and PM2.5 measurements in both cities (R2 0.3 in Dhaka, and 0.4 in Pittsburgh), and consistent within-city spatial patterns in different meteorological seasons. Compared to the Pittsburgh levels, both PNC and PM2.5 levels in Dhaka were significantly higher, however, PM2.5 was disproportionately higher (10–12 times higher) than PNC (3–4 times higher). The slope of PNC versus PM2.5 varied significantly between the two cities, suggesting that the sources and size distribution of particles that make up the majority of the PM2.5 were different in the two cities. The results found in Dhaka indicate that aerosol particles are influenced by solid fuel combustion, including solid biomass burning, waste burning, and road dust, which have a greater impact on particle mass concentration due to their larger size. Contrary, in Pittsburgh, traffic (gasoline and diesel combustion) particles, relatively smaller in size compared to solid fuel combustion particles, play a dominant role in determining the within-city variability of PNC and PM2.5. Our findings suggest that while controlling traffic emissions can contribute to reducing PNC, substantial efforts will be required to mitigate accumulation mode particles from various region-specific sources in order to decrease PM2.5 mass concentrations in Dhaka.

Characterization of emissions from axle-mounted rail disc brakes

The most important sources for non-exhaust emissions from railways are the contact strip, the contact wire, wheels, rails and brakes. It is expected that the major share of PM (particulate matter) emission can be assigned to the brakes. In order to quantify the emissions from railway brakes, a series of test bench tests was carried out. These tests aimed at a quantification and characterization of emissions for both sintered and organic brake pads. The measurement setup included monitoring of emitted particle mass and particle number (PN) in the size range from 10 nm to 32 µm. PM10 emission factors could be derived in the range from 0.11 g/km to 4.21 g/km. Emissions from organic brake pads were higher compared to those from sintered materials. The monitoring of particle number concentration showed a significant dependency of PN emissions from the surface temperatures as soon as a critical temperature was exceeded.

Effect of the pairing types and pairing strength on the ground state properties of even and odd Mg isotopes

This study is an investigation of the effect of the pairing strength using different types of pairing (surface, volume and mixed surface–volume pairing) on the ground state properties of even and odd Mg isotopes. The Hartree–Fock–Bogoliubov (HFB) theory and two types of Skyrme forces, SKI3 and SLY6, were employed in our calculations. The pairing strength values are modified at each execution of the HFBTHO code to obtain the experimental values of binding energy for the investigated even and odd isotopes separately. Then a new formula for pairing strength for each even and odd isotope independently for all the pairing, surface, volume and mixed surface–volume types is developed by fitting the pairing strength values to the mass number. Based on the newly generated formulas for pairing strength, some of the calculated ground state properties are found to depend strongly on the pairing strength values and the pairing type also plays an essential role in providing accurate results.

Simulation and optimization of a liquified petroleum gas sweetening process using Aspen HYSYS

Liquefied petroleum gas (LPG) is one of the common fossil fuels that can be derived from natural gas or crude oil. In either case, it contains impurities such as H2S and CO2, which should be removed to obtain sweet liquified petroleum gas with a pure concentration of hydrocarbons such as ethane, propane, and butane. The most common method of gas sweetening process is by using amine compounds, which come in various types, each designed for specific and selective removal of acidic gases. In this study, methyldiethanolamine (42 wt.%) was used as a solvent to extract approximately 0.8% of H2S from sour LPG at a temperature of 400C. The objective of this study focuses on simulating and optimizing the LPG sweetening unit using Aspen HYSYS V11 to investigate the different parameters that affect the separation of acidic gases and to achieve high profitability. The number of trays, circulation rates, temperature, mass and molar flow rates, and other parameters were studied to reduce the H2S concentration to 0% in the treated LPG stream. The sweetening process was proposed to produce LPG with high levels of specific preferred specifications such as calorific value and purity, in addition to being environmentally friendly.

A systematic review of risk factors and adverse outcomes associated with anterior cervical discectomy and fusion surgery over the past decade.

Anterior cervical discectomy and fusion (ACDF) is one of the most frequently performed cervical surgeries in the world, yet there have been several reported complications. To determine the actual incidence of complications related to ACDF as well as any risk variables that may have been identified in earlier research. To evaluate the origin, presentation, natural history, and management of the risks and the complications, we conducted a thorough assessment of the pertinent literature. An evaluation of clinical trials and case studies of patients who experienced one or more complications following ACDF surgery was done using a PubMed, Cochrane Library, and Google Scholar search. Studies involving adult human subjects that were written in the English language and published between 2012 and 2022 were included in the search. The search yielded 79 studies meeting our criteria. The overall rates of complications were as follows: Dysphagia 7.9%, psudarthrosis 5.8%, adjacent segment disease (ASD) 8.8%, esophageal perforations (EPs) 0.5%, graft or hardware failure 2.2%, infection 0.3%, recurrent laryngeal nerve palsy 1.7%, cerebrospinal fluid leak 0.8%, Horner syndrome 0.5%, hematoma 0.8%, and C5 palsy 1.9%. Results showed that dysphagia was a common postoperative sequelae with bone morphogenetic protein use and a higher number of surgical levels being the major risk factors. Pseudarthrosis rates varied depending on the factors such as asymptomatic radiographic graft sinking, neck pain, or radiculopathy necessitating revision surgery. The incidence of ASD indicated no data to support anterior cervical plating as more effective than standalone ACDF. EP was rare but frequently fatal, with no correlation found between patient age, sex, body mass index, operation time, or number of levels.

Proton and neutron density distributions at supranormal density in low- and medium-energy heavy-ion collisions. II. Central Pb + Pb collisions

This paper represents a continuation of our investigation into the limitations on total, proton, and neutron particle number densities, as well as the asymmetry of proton and neutron density distributions achievable in central heavy-ion collisions. We explore these aspects at low and medium energies within the framework of the Boltzmann-Uhlenbeck-Uehling (pBUU) transport and time-dependent Hartree-Fock (TDHF) models. Previous studies, focusing on symmetric and asymmetric collisions of Ca and Sn nuclei [1], and initial results on Pb-nuclei collisions [2], emphasized the role of the Coulomb interaction in these events. Our findings indicated that: (i) the highest total densities predicted at Ebeam=800 MeV/nucleon were on the order of ≈2.5ρ0 (ρ0=0.16fm−3), (ii) the proton-neutron asymmetry for maximal densities, δ=(ρnmax−ρpmax)/(ρnmax+ρpmax), did not generally exceed the asymmetry in the initial state of the collision at all beam energies and tended to decrease during the reaction, and (iii) a significant portion of this asymmetry had its microscopic origin in Coulomb forces, masking the pure nuclear contribution. These new findings, particularly relevant in the astrophysical context, are further examined in this work, focusing on the heaviest target-projectile combination Pb212,208 accessible in an experiment. We introduce the SkT3 Skyrme force model, not previously used for the Pb system, and compare it to the SV-bas and SV-sym34 models to explore the symmetry-energy dependence of the results. Contour plots of nucleonic densities are presented, contrasting the time evolution of the density distributions in low (TDHF) and high (pBUU) models. We also present the evolution of normalized maximal proton, neutron, and total nucleon number density with increasing beam energy in the full pBUU model and the Vlasov approximation, aiming to explore the impact of correlations in the reaction. The time evolution of the proton and neutron density distributions in the plane transverse to the beam direction is illustrated at both low and high beam energy. In conclusion, our detailed examination of the Pb system in this work provides further essential evidence that the aforementioned findings (i)–(iii) are only weakly dependent on system size and a symmetry-energy model, and thus, they are of more general importance. Published by the American Physical Society 2024

Systematics of fusion of light nuclei

We have constructed the empirical formula for fusion barrier height (VB), fusion barrier position (RB), and inverted parabola (ħω) of light nuclei with atomic number in the range 2≤ZC≤10. This formula is obtained by studying the fusion barrier characteristics of 333 projectile target combinations. The values produced by the present formula are also compared with experiments. The present semi-empirical formula produces fusion barrier characteristics of light nuclei with the simple inputs of mass number (A) and atomic number (Z) of projectile targets. This semi-empirical formula can be utilized to calculate and interpret fusion barrier characteristics in light nuclear systems.

Studying influence of the mathematical model error on the results of calculating freedom torsional vibration for marine diesel propulsion system

The Freedom Torsional Vibrations (FTV) Calculation (FTVC) for the marine main propulsion plant (MPP) to determine the freedom frequencies and the FTV formations of the mechanical system. Normally, the MPP is dynamically modeled as a finite n concentrated masses with the parameters of: Mass moment of inertia Jk (kgm2, k = 1÷ n) and the torsional stiffness Ck,k+1 (Nm/rad) between the k and k+1 concentrated masses. This paper studies the influence of the number of concentrated masses n as well as the accuracy of determining Jp (Moment of inertia of the propeller) on the solution of the MPP's FTVC. The research verifies to the MMP on the Korean ship XXX-XXX-XXX, using the MDE 6G70MEC. Keywords: Freedom Torsional Vibration (FTV); Mathematic model of the FTV; Exactness of the FTV calculation.

Isotopes: How did they all begin? Primordial nucleosynthesis: experimental study of the roles of neutrons

Light nuclei with mass number of below 8 are considered to be produced by the so-called the Big-bang nucleosynthesis (BBN) occurring in the early universe. Since BBN depends on various assumptions related to the origin of the universe and the laws of fundamental interactions and elementary particles, those assumptions can be verified by comparing the abundances of light isotopes calculated with BBN and the astronomically observed ones. Since the neutrons are the starting materials of BBN together with protons, and also they are electrically neutral, they play a unique and critical roles in BBN. In this paper status of the BBN analysis and experimental studies of the properties of neutrons relevant to BBN will be reviewed.

Propensity score matched analysis of functional outcome in five thousand cases of robot-assisted radical prostatectomy versus high-intensity focused ultrasound

BackgroundTo evaluate functional outcome after robot-assisted radical prostatectomy (RARP) and high-intensity focused ultrasound (HIFU) ablation for prostate cancer. MethodsWe retrospectively reviewed 4,983 RARP and 230 HIFU procedures performed at a single tertiary center. A 1:4 ratio propensity score matching (PSM) was performed to achieve baseline equivalence in age, body mass index (BMI), comorbidities, clinical stage, prostate specific antigen (PSA), prostate volume, biopsy grade, and number of positive cores. Functional outcomes based on International Prostate Symptom Score (IPSS), International Index of Erectile Function (IIEF-5) scores, and incontinence rates were evaluated at 6, 12, and 24 months. Resultstotal of 193 HIFU cases matched to 760 cases of RARP, were included. No differences were observed in perioperative IPSS at all follow-up periods. Despite comparative erectile function at baseline, HIFU showed significantly better erectile function preservation compared to RARP, with mean IIEF-5 scores of 9.5 versus 4.8, 9.5 versus 5.8, and 8.4 versus 6.7 at 6, 12, and 24 months, respectively (all P < 0.001). Pad-free rates at 6 and 12 months were comparable, with over 96% achieving continence at 12 months in both groups, although the rate of ≤1 pad/day at last follow-up was slightly better in HIFU (98.9% vs. 96.7%, P = 0.049). Subgroup analysis on partial (PGA) and whole gland ablation (WGA) showed no differences in IIEF-5 and incontinence but increased voiding difficulty in WGA versus PGA after 12 months of therapy (P < 0.05). Preoperative IIEF-5 ≥17 and HIFU were significant predictors of early erectile function recovery at 6 months (HR 4.4 and 5.0; all P < 0.001). No differences were observed in treatment-free survival between PGA, WGA, and RARP. ConclusionHIFU shows better performance in early recovery and preservation of erectile function after treatment for prostate cancer without increasing the risk of treatment failure. Patients with moderate to severe erectile dysfunction (IIEF-5 <17) prior to surgery should be warned of poor recovery after treatment.

A case report of extranodal diffuse large B-cell lymphoma involving upper limb soft tissue in a patient with rheumatoid arthritis on immunosuppressive therapy

An 80-year-old woman affected by rheumatoid arthritis on immunosuppressive therapy was evaluated for an 11-month history of swelling of her left upper limb. The patient did not report systemic symptoms. Ultrasonographic examination showed hypoechoic masses in the upper limb soft tissue, brachial vein thrombosis, and suspected malignant axillary lymphadenopathy. The patient underwent an excisional biopsy of the lymphadenopathy for histologic examination; a diagnosis of diffuse large B-cell lymphoma was made. The patient started anticoagulation therapy and chemotherapy, with a follow-up at a hematology clinic. At a 3-month follow-up visit in our clinic, the swelling of her left upper limb decreased, and an ultrasonographic control demonstrated a reduction in the size and number of the soft tissue masses and resolution of vein thrombosis.

Nuclear charge radius predictions based on eXtreme Gradient Boosting

Nuclear charge radii with 8 ≤ Z ≤ 100 are studied based on the eXtreme Gradient Boosting (XGBoost) method. Besides the proton, neutron, and mass numbers, the physical quantities related to the isospin, shell, and pairing effects are important to improve the performance of the XGBoost method by including them as the input variables. The XGBoost method describes the nuclear charge radii better than the Skyrme-Hartree–Fock-Bogoliubov (HFB)-21 model, especially for odd-Z nuclei. The root-mean-square deviation with respect to the experimental data is reduced from 0.025 fm of the HFB-21 model to 0.012 fm of the XGBoost method in the learning set. It is found that the XGBoost method has reliable extrapolation ability at least for the nuclei not far from the learning region, which is verified by comparison with the data in the newly measured experimental data. When extrapolated to the unknown region, the XGBoost predictions of charge radii are close to the HFB-21 results, and the deviations between them are generally less than 0.1 fm even within about 20 steps from the known region.

Prevalence and characters of post-acute COVID-19 syndrome in healthcare workers in Kashan/Iran 2023: a cross-sectional study

BackgroundPost-acute COVID-19 syndrome that is called long COVID-19 consists of the symptoms that last more than 12 weeks with no other explanation. The present study aimed to determine the prevalence, frequency of symptoms, and risk factors of long COVID-19 in the healthcare workers (HCWs) of a selected hospital in Kashan/Iran in 2023.MethodsA total of 350 HCWs with a history of COVID-19 infection were randomly recruited to the study from February to May 2023. Participants completed a questionnaire including demographic characteristics, information related to COVID-19 infection, underlying diseases, and a checklist of long COVID-19 symptoms. Mann‒Whitney U test, chi-square test, T‒tests, and binary logistic regression were used for data analysis by SPSS 16.ResultsThe results showed that 75.7% of HCWs experienced symptoms of long COVID-19. The most common symptoms were fatigue (53.1%), cough (43.1%) and muscle weakness (37.1%). In bivariate analysis job title, body mass index (BMI), frequency and number of symptoms of COVID-19 infection, preexisting disease, tobacco use, age, and years of experience showed a significant statistical association with long COVID-19. In binary logistic regression the number of symptoms during COVID-19 infection, nursing occupation, use of corticosteroids, and symptoms of dyspnea and loss of taste could explain the occurrence of long COVID-19.ConclusionThe long COVID-19 is a prevalent condition among HCWs especially nurses. Symptoms of long COVID-19 such as fatigue and cough can persists over time. This chronic condition has significant associations with different clinical risk factors.