Resolving the spurious-state problem in the Dirac equation with finite difference method

To solve the Dirac equation with the finite difference method, one has to face up to the spurious-state problem due to the fermion doubling problem when using the conventional central difference formula to calculate the first-order derivative on the equal interval lattices. This problem is resolved by replacing the central difference formula with the asymmetric difference formula, i.e., the backward or forward difference formula. To guarantee the hermitian of the Hamiltonian matrix, the backward and forward difference formula should be used alternatively according to the parity of the wavefunction. This provides a simple and efficient numerical prescription to solve various relativistic problems in the microscopic world.Comment: 11 pages, 2 figures, 1 tables, accepted by Physical Review C as a lette

Study on the nutritional evaluation and intervention of the elderly inpatients with chronic diseases

目的 探讨对老年慢病住院患者进行营养评估及干预的方式及效果评价。方法 采用“微型营养评价法”（MNA-SF）对≥65岁住院患者进行营养评估，筛选出营养不良/有营养不良风险的患者纳入研究范围，随机分组，分别给予传统健康教育干预方式和医护一体化形式的针对性营养干预。结果 干预后45d和90d对两组研究对象进行营养评估和饮食习惯的评价，45d营养复评结果无明显统计学差异，90d两组统计学结果显现差异性，观察组患者进食习惯有明显改善。结论 采用“微型营养评价法”（MNA-SF）对≥65岁住院患者进行营养筛查简单可行，医护一体化形式对营养不良及有营养不良风险的患者进行针对性干预，其效果优于传统健康教育干预模式。Objective:To discuss the method and effects of nutritional evaluation and intervention of hospitalized elderly patients with chronic diseases. Methods:The hospitalized patients over 65 were having the nutritional evaluation by using MNA–SF. Patients with malnutrition or at the risk of malnutrition were selected for research and assigned to observation group and control group at random . The traditional and medical integration health teaching interventions were used in the two groups separately. Results:Nutritional and eating habits evaluation were carried out in the two groups in 45 and 90 days after interventions. It showed that there was no statistically significant difference after45 days, but  after 90days there was a difference between the observation and control groups. Conclusion: MNA–SF is a simple and effective method for nutritional evaluation of hospitalized patients over 65. Medical integration health teaching interventions is better than traditional health teaching for patients with malnutrition or at the risk of malnutrition

Solitary pulmonary mass in a patient with a history of lymphoma: a case report

INTRODUCTION: With the progress made in treatments, the survival rate for patients with malignant lymphoma in the last 30 years has significantly improved. However, the risk of experiencing a second primary malignancy or other disease has increased significantly. CASE PRESENTATION: A 44-year-old Mongolian man with a large mass in his right lower abdomen was admitted to our hospital 15 years previously. The mass was removed, and confirmed via pathological examination to be a malignant B-cell lymphoma in the appendix and distal small bowel. Post-operative chemotherapy with standard cyclophosphamide, hydroxydaunomycin, vincristine (Oncovin®) and prednisolone regimen was given for six cycles. No obvious recurrence was detected over the following 12 years. Subsequently, a mass in the right lung was found on a regular X-ray follow-up; our patient did not report chills, fever or cough. Chest computed tomography and positron emission tomography scans confirmed the mass. A primary lung carcinoma was considered to be the most likely diagnosis. However, after an exploratory thoracotomy and right upper lobectomy was performed a pathological examination of tissue samples demonstrated a lung cryptococcal granuloma, with positive staining for periodic acid Schiff and periodic acid-silver metheramine. CONCLUSIONS: Compared to the normal population, second primary malignancy (in particular leukaemia and lung cancer) in patients with malignant lymphoma during their long-term survival has been seen occasionally. However, other diagnoses should also be considered such as pulmonary cryptococcosis. Other than computed-tomography-guided needle biopsy, surgery for some patients is a much more appropriate choice, which could also help attain correct diagnosis and treatment