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1.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-335007

ABSTRACT

The continuous emergence of novel SARS-CoV-2 variants poses new challenges to the fight against the COVID-19 pandemic. The newly emerging Omicron strain caused serious immune escape and raised unprecedented concern all over the world. The development of antibody targeting conserved and universal epitope is urgently needed. A subset neutralizing antibody(nAbs) against COVID-19 from convalescent patients were isolated in our previous study. Here in this study, we investigated the accommodation of these nAbs to SARS-CoV-2 variants of concerns (VOCs), revealing that IgG 553-49 neutralizes pseudovirus of SARS-CoV-2 Omicron variant. In addition, we determined the cryo-EM structure of SARS-CoV-2 spike complexed with three antibodies targeting different epitopes, including 553-49, 553-15 and 553-60. Notably, 553-49 targets a novel conserved epitope and neutralizes virus by disassembling spike trimers. 553-15, an antibody that neutralizes all the other VOCs except omicron, cross-links two spike trimers to form trimer dimer, demonstrating that 553-15 neutralizes virus by steric hindrance and virion aggregation. These findings suggest the potential to develop 49 and other antibody targeting this highly conserved epitope as promising cocktail therapeutics reagent for COVID-19.

2.
American Journal of Hospice and Palliative Medicine® ; : 10499091221084653, 2022.
Article in English | Sage | ID: covidwho-1820074

ABSTRACT

The role of early Do Not Resuscitate (DNR) in hospitalized older adults (OAs) with SARS-CoV-2 infection is unknown. The objective of the study was to identify characteristics and outcomes associated with early DNR in hospitalized OAs with SARS-CoV-2. We conducted a retrospective chart review of older adults (65+) hospitalized with COVID-19 in New York, USA, between March 1, 2020, and April 20, 2020. Patient characteristics and hospital outcomes were collected. Early DNR (within 24 hours of admission) was compared to non-early DNR (late DNR, after 24 hours of admission, or no DNR). Outcomes included hospital morbidity and mortality. Of 4961 patients, early DNR prevalence was 5.7% (n = 283). Compared to non-early DNR, the early DNR group was older (85.0 vs 76.8, P < .001), women (51.2% vs 43.6%, P = .012), with higher comorbidity index (3.88 vs 3.36, P < .001), facility-based (49.1% vs 19.1%, P < .001), with dementia (13.3% vs 4.6%, P < .001), and severely ill on presentation (57.9% vs 32.3%, P < .001). In multivariable analyses, the early DNR group had higher mortality risk (OR: 2.94, 95% CI: 2.10?4.11), less hospital delirium (OR: 0.55, 95% CI: 0.40?.77), lower use of invasive mechanical ventilation (IMV, OR: 0.37, 95% CI: .21?.67), and shorter length of stay (LOS, 4.8 vs 10.3 days, P < .001), compared to non-early DNR. Regarding early vs late DNR, while there was no difference in mortality (OR: 1.12, 95% CI: 0.85?1.62), the early DNR group experienced less delirium (OR: 0.55, 95% CI: .40?.75), IMV (OR: 0.53, 95% CI: 0.29?.96), and shorter LOS (4.82 vs 10.63 days, OR: 0.35, 95% CI: 0.30?.41). In conclusion, early DNR prevalence in hospitalized OAs with COVID-19 was low, and compared to non-early DNR is associated with higher mortality but lower morbidity.

3.
Future Virology ; 2022.
Article in English | PMC | ID: covidwho-1817855

ABSTRACT

COVID-19, which was first reported in December 2019 in China, has caused a global outbreak. Five variants of concern (VOCs) have been identified in different countries since the global pandemic, namely, Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), Delta (B.1.617.2) and Omicron (B.1.529). Although multiple vaccines have been found to be effective, some of the amino acid changes may increase the infectivity of virus and decrease the sensitivity to antibodies. Here we characterize the VOCs and discuss their sensitivity to antibodies elicited by convalescent and vaccinee sera. In conclusion, several variants display a reduction in the susceptibility to neutralization antibodies generated by natural infection or vaccination, which threatens the containment of the epidemic.

4.
Computational & Mathematical Methods in Medicine ; : 1-6, 2022.
Article in English | Academic Search Complete | ID: covidwho-1807692

ABSTRACT

Objective. To analyze the effect of an intelligent medical management platform combined with perioperative detailed nursing on cognitive ability, postoperative complications, and quality of life (QOL) of patients undergoing hysterectomy. Methods. The clinical data of 76 patients undergoing hysterectomy in our hospital from December 2019 to December 2021 were selected for the retrospective analysis, and the patients were divided into the experimental group (EG, n = 38 , intelligent medical management platform+perioperative detailed nursing) and the routine group (RG, n = 38 , routine nursing) according to their admission order, and the cognition of disease and QOL after intervention of patients in the two groups were evaluated by the self-proposed questionnaire on cognition of disease of our hospital and the MOS 36-item short-form health survey (SF-36). Results. After intervention, the scores on cognitive ability, various nursing items, and QOL were significantly higher in EG than in RG (P < 0.001), and during the study, the total incidence rate of complications was significantly lower in EG than in RG (P < 0.05). Conclusion. Combining an intelligent medical management platform with perioperative detailed nursing is a reliable method to improve QOL and reduce postoperative complications for patients undergoing hysterectomy. Further research will be conducive to providing a reliable perioperative intervention scheme for such patients. [ FROM AUTHOR] Copyright of Computational & Mathematical Methods in Medicine is the property of Hindawi Limited and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

5.
Cell ; 185(8): 1389-1401.e18, 2022 Apr 14.
Article in English | MEDLINE | ID: covidwho-1788017

ABSTRACT

The effectiveness of SARS-CoV-2 vaccines and therapeutic antibodies have been limited by the continuous emergence of viral variants and by the restricted diffusion of antibodies from circulation into the sites of respiratory virus infection. Here, we report the identification of two highly conserved regions on the Omicron variant receptor-binding domain recognized by broadly neutralizing antibodies. Furthermore, we generated a bispecific single-domain antibody that was able to simultaneously and synergistically bind these two regions on a single Omicron variant receptor-binding domain as revealed by cryo-EM structures. We demonstrated that this bispecific antibody can be effectively delivered to lung via inhalation administration and exhibits exquisite neutralization breadth and therapeutic efficacy in mouse models of SARS-CoV-2 infections. Importantly, this study also deciphered an uncommon and highly conserved cryptic epitope within the spike trimeric interface that may have implications for the design of broadly protective SARS-CoV-2 vaccines and therapeutics.

7.
Acta Pharmacol Sin ; 2022 Mar 16.
Article in English | MEDLINE | ID: covidwho-1747246

ABSTRACT

VV116 (JT001) is an oral drug candidate of nucleoside analog against SARS-CoV-2. The purpose of the three phase I studies was to evaluate the safety, tolerability, and pharmacokinetics of single and multiple ascending oral doses of VV116 in healthy subjects, as well as the effect of food on the pharmacokinetics and safety of VV116. Three studies were launched sequentially: Study 1 (single ascending-dose study, SAD), Study 2 (multiple ascending-dose study, MAD), and Study 3 (food-effect study, FE). A total of 86 healthy subjects were enrolled in the studies. VV116 tablets or placebo were administered per protocol requirements. Blood samples were collected at the scheduled time points for pharmacokinetic analysis. 116-N1, the metabolite of VV116, was detected in plasma and calculated for the PK parameters. In SAD, AUC and Cmax increased in an approximately dose-proportional manner in the dose range of 25-800 mg. T1/2 was within 4.80-6.95 h. In MAD, the accumulation ratio for Cmax and AUC indicated a slight accumulation upon repeated dosing of VV116. In FE, the standard meal had no effect on Cmax and AUC of VV116. No serious adverse event occurred in the studies, and no subject withdrew from the studies due to adverse events. Thus, VV116 exhibited satisfactory safety and tolerability in healthy subjects, which supports the continued investigation of VV116 in patients with COVID-19.

8.
Euro Surveill ; 27(10)2022 03.
Article in English | MEDLINE | ID: covidwho-1742166

ABSTRACT

BackgroundThe Delta variant of SARS-CoV-2 had become predominant globally by November 2021.AimWe evaluated transmission dynamics and epidemiological characteristics of the Delta variant in an outbreak in southern China.MethodsData on confirmed COVID-19 cases and their close contacts were retrospectively collected from the outbreak that occurred in Guangdong, China in May and June 2021. Key epidemiological parameters, temporal trend of viral loads and secondary attack rates were estimated. We also evaluated the association of vaccination with viral load and transmission.ResultsWe identified 167 patients infected with the Delta variant in the Guangdong outbreak. Mean estimates of latent and incubation period were 3.9 days and 5.8 days, respectively. Relatively higher viral load was observed in infections with Delta than in infections with wild-type SARS-CoV-2. Secondary attack rate among close contacts of cases with Delta was 1.4%, and 73.1% (95% credible interval (CrI): 32.9-91.4) of the transmissions occurred before onset. Index cases without vaccination (adjusted odds ratio (aOR): 2.84; 95% CI: 1.19-8.45) or with an incomplete vaccination series (aOR: 6.02; 95% CI: 2.45-18.16) were more likely to transmit infection to their contacts than those who had received the complete primary vaccination series.DiscussionPatients infected with the Delta variant had more rapid symptom onset compared with the wild type. The time-varying serial interval should be accounted for in estimation of reproduction numbers. The higher viral load and higher risk of pre-symptomatic transmission indicated the challenges in control of infections with the Delta variant.


Subject(s)
COVID-19 , SARS-CoV-2 , COVID-19/epidemiology , China/epidemiology , Humans , Retrospective Studies , SARS-CoV-2/genetics
9.
Antimicrobial Agents and Chemotherapy ; 64(6), 2020.
Article in English | GIM | ID: covidwho-1723508

ABSTRACT

Novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) lies behind the ongoing outbreak of coronavirus disease 2019 (COVID-19). There is a growing understanding of SARS-CoV-2 in virology, epidemiology, and clinical management strategies. However, no anti-SARS-CoV-2 drug or vaccine has been officially approved due to the absence of adequate evidence. Scientists are racing to develop a treatment for COVID-19. Recent studies have revealed many attractive therapeutic options, even if some of them remain to be further confirmed in rigorous preclinical models and clinical trials. In this minireview, we aim to summarize the updated potential approaches against SARS-CoV-2. We emphasize that further efforts are warranted to develop the safest and most effective approach.

10.
Polymers (Basel) ; 14(5)2022 Feb 28.
Article in English | MEDLINE | ID: covidwho-1715620

ABSTRACT

Chitosan is a biodegradable natural polymer derived from the exoskeleton of crustaceans. Because of its biocompatibility and non-biotoxicity, chitosan is widely used in the fields of medicine and agriculture. With the latest technology and technological progress, different active functional groups can be connected by modification, surface modification, or other configurations with various physical, chemical, and biological properties. These changes can significantly expand the application range and efficacy of chitosan polymers. This paper reviews the different uses of chitosan, such as catheter bridging to repair nerve broken ends, making wound auxiliaries, as tissue engineering repair materials for bone or cartilage, or as carriers for a variety of drugs to expand the volume or slow-release and even show potential in the fight against COVID-19. In addition, it is also discussed that chitosan in agriculture can improve the growth of crops and can be used as an antioxidant coating because its natural antibacterial properties are used alone or in conjunction with a variety of endophytic bacteria and metal ions. Generally speaking, chitosan is a kind of polymer material with excellent development prospects in medicine and agriculture.

11.
EuropePMC;
Preprint in English | EuropePMC | ID: ppcovidwho-328726

ABSTRACT

Enveloped viruses, including human immunodeficiency virus (HIV) and SARS-CoV-2, target cells through membrane fusion process. The detailed understanding of the process is sought after for vaccine development but remains elusive due to current technique limitations for direct three-dimensional (3D) imaging of an individual virus during its viral entry. Recently, we developed a simple specimen preparation method for real-time imaging of metal dynamic liquid-vaper interface at nanometer resolution by transmission electron microscopy (TEM). Here, we extended this method to study biology sample through snapshot 3D structure of a single HIV (pseudo-typed with the envelope glycoprotein of vesicular stomatitis virus, VSV-G) at its intermediate stage of viral entry to HeLa cells in a liquid-phase environment. By individual-particle electron tomography (IPET), we found the viral surface release excess lipids with unbound viral spike proteins forming ~50-nm nanoparticles instead of merging cell membrane. Moreover, the spherical-shape shell formed by matrix proteins underneath the viral envelope does not disassemble into a cone shape right after fusion. The snapshot 3D imaging of a single virus provides us a direct structure-based understanding of the viral entry mechanism, which can be used to examine other viruses to support the development of vaccines combatting the current ongoing pandemic.

12.
EuropePMC;
Preprint in English | EuropePMC | ID: ppcovidwho-327270

ABSTRACT

The highly mutated and transmissible Omicron variant has provoked serious concerns over its decreased sensitivity to the current coronavirus disease 2019 (COVID-19) vaccines and evasion from most anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) neutralizing antibodies (NAbs). In this study, we explored the possibility of combatting the Omicron variant by constructing bispecific antibodies based on non-Omicron NAbs. We engineered ten IgG-like bispecific antibodies with non-Omicron NAbs named GW01, 16L9, 4L12, and REGN10987 by fusing the single-chain variable fragments (scFvs) of two antibodies through a linker and then connecting them to the Fc region of IgG1. Surprisingly, eight out of ten bispecific antibodies showed high binding affinity to the Omicron receptor-binding domain (RBD) and exhibited extreme breadth and potency against pseudotyped SARS-CoV-2 variants of concern (VOCs) including Omicron, as well as authentic Omicron(+R346K) variants. Six bispecific antibodies containing the cross-NAb GW01 neutralized Omicron variant and retained their abilities to neutralize other sarbecoviruses. Bispecific antibodies inhibited Omicron infection by binding to the ACE2 binding site. A cryo-electron microscopy (cryo-EM) structure study of the representative bispecific antibody FD01 in complex with the Omicron spike (S) revealed 5 distinct trimers and one unique bi-trimer conformation. The structure and mapping analyses of 34 Omicron S variant single mutants elucidated that two scFvs of the bispecific antibody synergistically induced the RBD-down conformation into 3-RBD-up conformation, enlarged the interface area, accommodated the S371L mutation, improved the affinity between a single IgG and the Omicron RBD, and hindered ACE2 binding by forming bi-trimer conformation. Our study offers an important foundation for anti-Omicron NAb design. Engineering bispecific antibodies based on non-Omicron NAbs may provide an efficient solution to combat the Omicron variant.

14.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-325205

ABSTRACT

Background: An increased risk of venous thromboembolism (VTE) in patients with coronavirus disease 2019 (COVID-19) has been reported. We performed a meta-analysis to evaluate the prevalence of VTE in COVID-19 patients. Methods: : The PubMed and Embase databases were searched for studies reporting VTE in COVID-19 patients up to June 27, 2020. The selected studies were predefined into the “suspected screening group” and the “routine screening group.” The VTE prevalence was calculated using random-effect models. Results: : We selected 20 studies including a total of 2763 COVID-19 patients. In 2203 COVID-19 patients from the suspected screening group, the pool VTE incidence was 15.2% (95% confidence interval [CI]: 10.5–21.6%). In 560 COVID-19 patients from the routine screening group, the VTE prevalence was 40.8% (95% CI: 20.6–64.7%). Furthermore, the VTE incidence of critically ill COVID-19 patients from the two groups was 19.6% and 61.4%, respectively, which indicates that critically ill COVID-19 patients were more susceptible to VTE. Conclusions: : A high incidence of VTE was observed in COVID-19 patients, especially in severe cases. The incidence of VTE in COVID-19 patients from the routine screening group was higher than that in patients from the suspected screening group. This indicates that a lower threshold of suspicion to perform VTE imaging tests may be reasonable and there is an urgent need to adapt a regular screening strategy for VTE.

15.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-325144

ABSTRACT

Background: Increasing evidence revealed that kidney was one of the targets of SARS-CoV-2. However, the incidences of kidney abnormalities were significantly different, from 0.5 to 75.4% in coronavirus disease 2019 (COVID-19) patients. The association of kidney injury with prognosis remain controversial. Methods: : In this retrospective cohort study, laboratory confirmedCOVID-19inpatients with severe type were enrolled. Demographic, clinicaland laboratory data were collected. Association of estimated glomerular fifiltration rate (eGFR)with 28-days mortality was analyzed. Results: : The total 28-days mortality of hospitalizationwas 22.3% (79/354). Non-survivors had a significantly declined eGFR levels than survivors (75.95 [IQR: 47.22,92.84] ml/min/1.73m 2 vs. 96.43 [IQR: 84.11,108.47] ml/min/1.73m 2 , P <0.001). The 28-days mortality in declined eGFR group (<90 ml/min/1.73m 2 ) was significantly higher than that in normal eGFR group (38.5% vs. 10.7%, P <0.001). Multivariate logistic regression revealed that the independent risk factors of 28-days outcome included lower eGFR (OR: 3.97, 95%CI: 1.42-11.11), elevated WBC (OR: 7.08, 95%CI: 3.15-15.90), lymphopenia (OR: 2.58, 95%CI: 1.21-5.49)andIL-6 (OR: 7.90, 95%CI: 2.19-28.49). Kaplan-Meier analysis indicated the survival disadvantage in patients with declined eGFR. ROC curve showed the eGFR cut-off value for predicting 28-days death was 82.2 μmol/L, with the sensitivity of 76.7% and speciality of 66.3%. Conclusion: Declined eGFR was associated with poor prognosis and could be used an independent risk factor of 28-days mortality in COVID-19 patients. Early detection and surveillance for eGFR may benefit to identify patients with high-risk ofprogression.

16.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-321698

ABSTRACT

Background: Age has been implicated as the main risk factor for COVID-19-related mortality. Our objective was to determine patient factors associated with mortality in hospitalized older adults with COVID-19. Methods: : Retrospective cohort study of adults age 65+ (N=4,949) hospitalized with COVID-19 in the greater New York metropolitan area between 3/1/20-4/20/20. Data included patient demographics and clinical presentation. Multivariate logistic regression was used to evaluate associations. Results: : Average age 77.3 (SD=8.4), 56.0% male, 20.8% African American, 15.1% Hispanic. In a multivariate analysis, male gender (OR=1.47), higher comorbidity index (OR=1.10), admission from a facility (lower baseline function;OR=1.71), early DNR (declining life-sustaining treatments, OR=2.45), and higher illness severity (higher MEWS, OR=6.26, and higher oxygen requirements, OR=15.00) were associated with mortality, while age was not (p = 0.22). Conclusion: Our findings highlight the need to look beyond age in hospitalized older adults with COVID-19 when considering prognosis and treatment decisions.

17.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-313137

ABSTRACT

Background:  Understanding heterogeneity seen in patients with COVIDARDS and comparing to non-COVIDARDS may inform tailored treatments.  Methods:  A multidisciplinary team of frontline clinicians and data scientists worked to create the Northwell COVIDARDS dataset (NorthCARDS) leveraging over 11,542 COVID-19 hospital admissions. The data was then summarized to examine descriptive differences based on clinically meaningful categories of lung compliance, and to examine trends in oxygenation. Findings:  Of the 1595 COVIDARDS patients in the NorthCARDS dataset, there were 538 (34·6%) who had very low lung compliance (<20ml/cmH 2 O), 982 (63·2%) with low-normal compliance (20-50ml/cmH 2 O), and 34 (2·2%) with high lung compliance (>50ml/cmH 2 O). The very low compliance group had double the median time to intubation compared to the low-normal group (107 hours (IQR 26·3, 238·3) vs. 37·9 hours (IQR 4·8, 90·7)). Overall, 67·5% (n=1049) of the patients died during the hospitalization. In comparison to non-COVIDARDS reports, there were less patients in the high compliance category (2.2%vs.12%, compliance ≥50mL/cmH20), and more patients with P/F ≤ 150 (57·8% vs. 45.6%). No correlation was apparent between lung compliance and P/F ratio. The Oxygenation Index was similar, (11·12(SD 5·67) vs.12·8(SD 10·8)). 1  

18.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-308350

ABSTRACT

Background: Coronavirus disease 2019 (COVID-19) has emerged as a major global health threat with a great number of deaths worldwide. Acute kidney injury (AKI) is a common complication in patients admitted to the intensive care unit. We aimed toassess the incidence, risk factors and in-hospital outcomes of AKI in COVID-19 patients admitted to intensive care unit Methods: : we conducted a retrospective observational study in intensive care unit of Tongji hospital, which was assigned responsibility for the treatments of severe COVID-19 patients by Wuhan government. The AKI was defined and staged based onKidney Disease: Improving Global Outcomes (KDIGO) criteria. Mild AKI was defined as stage 1, and severe AKI was defined as stage 2 or stage 3. We used logistic regression analysis to evaluate AKI risk factors and the association between AKI and in-hospital mortality. Results: : A total of 150 patients with COVID-19 were included in our study. The median age of patients was 70 (interquartile range, 60-80) years and 62.7% were male. 70 (46.7%) patients developed AKI during hospitalization, corresponding to the 17.3% in stage 1 and 9.3% in stage 2 and 20.0% in stage 3, respectively. Compared to patients without AKI, patients with AKI had higher proportion of mechanical ventilation mortality and higher in-hospital mortality. 95.5% patients with severe AKI received mechanical ventilation and in-hospital mortality was up to 79.5%. Severe AKI was independently associated with high in-hospital mortality (OR: 4.30;95% CI: 1.83-10.10). Logistic regression analysis demonstrated that high serum interleukin-6 (OR: 2.54;95%CI: 1.00-6.42) and interleukin-10 (OR: 3.02;95%CI: 1.17-7.82) were risk factors for severe AKI development. Conclusions: : severe AKI was associated with high in-hospital mortality and inflammatory response may play a role in AKI development in critically ill patients with COVID-19.

19.
BMC Pulm Med ; 22(1): 51, 2022 Feb 04.
Article in English | MEDLINE | ID: covidwho-1666648

ABSTRACT

BACKGROUND: Understanding heterogeneity seen in patients with COVIDARDS and comparing to non-COVIDARDS may inform tailored treatments. METHODS: A multidisciplinary team of frontline clinicians and data scientists worked to create the Northwell COVIDARDS dataset (NorthCARDS) leveraging over 11,542 COVID-19 hospital admissions. The data was then summarized to examine descriptive differences based on clinically meaningful categories of lung compliance, and to examine trends in oxygenation. FINDINGS: Of the 1536 COVIDARDS patients in the NorthCARDS dataset, there were 531 (34.6%) who had very low lung compliance (< 20 ml/cmH2O), 970 (63.2%) with low-normal compliance (20-50 ml/cmH2O), and 35 (2.2%) with high lung compliance (> 50 ml/cmH2O). The very low compliance group had double the median time to intubation compared to the low-normal group (107.3 h (IQR 25.8, 239.2) vs. 39.5 h (IQR 5.4, 91.6)). Overall, 68.8% (n = 1057) of the patients died during hospitalization. In comparison to non-COVIDARDS reports, there were less patients in the high compliance category (2.2% vs. 12%, compliance ≥ 50 mL/cmH20), and more patients with P/F ≤ 150 (59.8% vs. 45.6%). There is a statistically significant correlation between compliance and P/F ratio. The Oxygenation Index is the highest in the very low compliance group (12.51, SD(6.15)), and lowest in high compliance group (8.78, SD(4.93)). CONCLUSIONS: The respiratory system compliance distribution of COVIDARDS is similar to non-COVIDARDS. In some patients, there may be a relation between time to intubation and duration of high levels of supplemental oxygen treatment on trajectory of lung compliance.


Subject(s)
COVID-19/physiopathology , Hypoxia/virology , Lung/physiopathology , Respiratory Distress Syndrome/virology , Adult , Aged , Aged, 80 and over , Biomechanical Phenomena , COVID-19/therapy , Case-Control Studies , Disease Progression , Female , Humans , Hypoxia/physiopathology , Hypoxia/therapy , Male , Middle Aged , Respiration, Artificial , Respiratory Distress Syndrome/physiopathology , Respiratory Distress Syndrome/therapy , Respiratory Function Tests , Retrospective Studies , Treatment Outcome
20.
Algorithms ; 15(2):39, 2022.
Article in English | MDPI | ID: covidwho-1650881

ABSTRACT

The high efficiency, flexibility, and low cost of robots provide huge opportunities for the application and development of intelligent logistics. Especially during the COVID-19 pandemic, the non-contact nature of robots effectively helped with preventing the spread of the epidemic. Task allocation and path planning according to actual problems is one of the most important problems faced by robots in intelligent logistics. In the distribution, the robots have the fundamental characteristics of battery capacity limitation, limited load capacity, and load affecting transportation capacity. So, a smart community logistics service framework is proposed based on control system, automatic replenishment platform, network communication method, and coordinated distribution optimization technology, and a Mixed Integer Linear Programming (MILP) model is developed for the collaborative and persistent delivery of a multiple-depot vehicle routing problem with time window (MDVRPTW) of swarm robots. In order to solve this problem, a hybrid algorithm of genetically improved set-based particle swarm optimization (S-GAIPSO) is designed and tested with numerical cases. Experimental results show that, Compared to CPLEX, S-GAIPSO has achieved gaps of 0.157%, 1.097%, and 2.077% on average, respectively, when there are 5, 10, and 20 tasks. S-GAIPSO can obtain the optimal or near-optimal solution in less than 0.35 s, and the required CPU time slowly increases as the scale increases. Thus, it provides utility for real-time use by handling a large-scale problem in a short time.

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