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Problem definitionThis paper considers how to allocate COVID-19 vaccines to different age groups when limited vaccines are available over time. Academic/practical relevanceVaccine is one of the most effective interventions to contain the ongoing COVID-19 pandemic. However, the initial supply of the COVID-19 vaccine will be limited. An urgent problem for the government is to determine who to get the first dose of the future COVID-19 vaccine. MethodologyWe use epidemic data from New York City to calibrate an age-structured SAPHIRE model that captures the disease dynamics within and across various age groups. The model and data allow us to derive effective static and dynamic vaccine allocation policies minimizing the number of confirmed cases or the numbers of deaths. ResultsThe optimal static policies achieve a much smaller number of confirmed cases and deaths compared to other static benchmark policies including the pro rata policy. Dynamic allocation policies, including various versions of the myopic policy, significantly improve on static policies. Managerial implicationsFor static policies, our numerical study shows that prioritizing the older groups is beneficial to reduce deaths while prioritizing younger groups is beneficial to avert infections. For dynamic policies, the older groups should be vaccinated at early days and then switch to younger groups. Our analysis provides insights on how to allocate vaccines to the various age groups, which is tightly connected to the decision-makers objective.
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Objective To investigate the resection of chest wall tumor and the reconstruction of it.Methods Retrospectively summarize the diagnosis and treatment of 91 cases of chest wall tumors in our hospital from January 2008 to November 2017.There are 55 males and 36 females and the ages ranged from 7 to 78 years,with a median age of 43 years.82 cases were operated for the first time,and 9 cases were reoperated.The postoperative pathology showed that the benign were 52 cases and malignant were 39 cases.The largest benign tumor was 15 cm × 10 cm × 3 cm and the largest malignant tumor was 30 cm × 20 cm × 15 cm.Local excision was performed in 66 cases and extended resection in 25 cases.After the resection,ilium,titanium mesh,Dacron mesh and Matrix reconstruction system were selected for reconstruction of chest wall respectivly.Results All the operation was successful and without death.Local resection was performed in all of benign tumor and in 15 cases of malignant tumor,extended resection was performed in the other 24 malignant tumor cases.After the local resection,the soft tissue was sutured directly to reconstruct the chest wall.The enlarged resection of the bone was performed by reconstructing the bony chest with different materials.In the soft tissue reconstruction,1 cases were treated with myocutaneous flap,and the other 23 cases were sutured directly.Postoperative chest wall integrity is stable,no chest wall floating and abnormal breathing.1 patients received ventilator supportion,and 2 patients had wound infection.The chest wall defect caused by benign tumor has good quality of life,no recurrence.After resection of the malignant tumor of the chest wall,2 died,and the rest were still alive.Conclusion Local resection is the main therapeutic method of benign chest wall tumor,and malignant chest wall tumor is mostly enlarged excision.Bone remodeling after extended resection plays an important role in the reconstruction of chest wall.It is necessary to select appropriate materials for reconstruction.Matrix titanium sternal or rib reconstruction system fixed reliably and the follow-up in a short term were also satisfactory.
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Objective To compare the therapeutic effects of endoscopy,TEM,and transanal local resection in rectal adenomatous polyps.Methods Data of 195 patients with rectal adenomatous polypus,who underwent either endoscopic resection (EMR,ESD and conventional endoscopic resection,n =65),TEM (n =65) or transanal local resection (n =65) in the past two years (2009-2011) were retrospectively collected and analyzed.Results Distance from lesion to anus in endoscopic group was significantly longer than that in transanal group (P ＜ 0.05).Bleeding volume during the procedure in transanal group was significantly larger than that in endoscopic group (P ＜ 0.05).The operation time and hospitalization time in endoscopic group were significantly shorter than those in TEM group and transanal group (P ＜ 0.01).The total cost in endoscopic group was significantly lower than that in other 2 groups (P ＜ 0.01).Conclusion Endoscopic resection is a safe and effective therapy for rectal adenomatous polypus.
