The analysis of stable nitrogen isotopic composition (δ15 N) of individual amino acid was recognized as an effective method for estimating the trophic level of organisms and detecting the nitrogen flow in food webs. In this study, we evaluated a two-stage procedure of esterification followed by acylation, in which biological samples underwent hydrolysis in acid and the released individual amino acids were derivative into the corresponding N-pivaloyl-iso-propyl ( NPP ) esters for gas chromatography-combustion-isotope ratio mass spectrometric ( GC-C-IRMS) analysis. A total of 13 kinds of individual amino acid derivatives were baseline separated on a nonpolar gas chromatography column (DB-5ms). The amount of sample for each test was not less than 20 ng N on column. High correlations were observed between the δ15 N values respectively obtained by GC-C-IRMS and element analysis-isotope ration mass spectrometry (EA-IRMS). Furthermore, the mean precision of this method was better than 1‰. Cation-exchange chromatograph was used to purify the samples, and the difference of the detection δ15 N values before and after purification by the resin was within 1‰. This method was applied to estimate the trophic level of various natural freshwater organisms from Aha Lake. The present study provided a new idea for the application of stable nitrogen isotope (δ15 N ) in the trophic level estimation of organisms and metabolism analysis of amino acid.

Immediate breast reconstruction with pedicle great omentum metasasis is safe,easy to perform, and has extensive clinical indications, less postoperative complications. The shape of reconstructed breast is plump and symmetrical, which is the optimal choice for reconstruction surgery with small and medium-sized breast at present. The surgical methods and effects of breast reconstruction with pedicle great omentum metastasis in 5 patients are reported in this article. Combined with the previous literature, the feasibility and safety of surgery is discussed, which provide a reference to clinicians.

Objective To study the application of pectoralis majoris fascia combined with serratus anterior fatty fascia flap in immediate breast reconstruction (IBR).Methods 40 patients with early breast cancer were divided into three groups according to indications and their own requirements.11 cases got implants combined with the pectoralis majoris fascia and the serratus anterior fatty fascia flap as a biological membrance,5 patients got latissimus dorsi myocutaneous flap reconstruction,and 24 cases underwent simple mastectomy.The three groups underwent routine sentinel lymph node biopsy.The operation time,subcutaneous drainage volume,drainage time,discharge time,postoperative pain score,infection of incision and patients' satisfaction were compared between the three groups.Results The reconstruction that used implants with pectoralis majoris fascia and serratus anterior fatty fascia flap as a biological membrance had the shortest recovery time,and the least subcutaneous fluid,and the differences were statistically significant(P＜0.05).The difference of incision infection had no statistical significance (P＞0.05).The difference of postoperative pain score and satisfaction had no statistical significance between fascia group and altissimo doris group (P＞0.05).Conclusion The technique of the prosthetic reconstruction of the pectoralis majoris fascia combined with the serratus anterior fatty fascia flap as a biological membrance is simple and safe,with small trauma,quick recovery and high patients' satisfaction,and can be widely used in clinical practice.

Objective To investigate the influences of culture conditions on the in vitro induction and maturation of dendritic cells by using different combinations of cytokines. -ethods Mouse bone mar-row cells were isolated and cultured in media containing varying combinations of cytokines, including granu-locyte-macrophage colony stimulating factor (GM-CSF), interleukin-4 (IL-4) and fms-like tyrosine kinase 3 ligand (Flt3L). After cultured at 37℃ for seven days, the attached bone marrow cells were collected and stained by fluorescence-labeled monoclonal antibodies (McAb) against CD11c, MHCⅡ and CD86 for flow cytometry analysis. In the parallel group, LPS was added on day 5 to a final concentration of 1μg/ml for DC maturation analysis by flow cytometry. Results In group Flt3L (20 ng/ml)/GM-CSF (20 ng/ml)/IL-4 (10 ng/ml), 90％ of bone marrow cells were CD11c-positive. Flt3L (100 ng/ml) could induce 88％ of bone marrow cells to express CD11c. Bone marrow cells positive for MHCⅡ accounted for 35. 4％ and 36. 1％ in group Flt3L/GM-CSF/IL-4 and group Flt3L/GM-CSF, where both Flt3L and GM-CSF were used at a concentration of 20 ng/ml. After LPS stimulation, the positive rates of MHCⅡ in group Flt3L/GM-CSF/IL-4 and group Flt3L/GM-CSF were 58. 1％ and 59. 6％, which increased by 22. 7％ and 23. 5％, re-spectively. The percentages of CD86-positive bone marrow cells were 7. 1％ and 5. 5％ in group Flt3L/GM-CSF/IL-4 and group Flt3L/GM-CSF. Bone marrow cells positive for CD86 grew by 7. 1％ and 6. 2％ in group Flt3L (20 ng/ml) and group GM-CSF/IL-4 after LPS stimulation. Conclusions Flt3L and GM-CSF probably dominated the differentiation and maturation of bone marrow-derived dendritic cells with a synergis-tic effect. Combined usage of Flt3L and GM-CSF at the concentration of 20 ng/ml would be an optimal proto-col for DC research.

Objective To investigate the effect of early thoracic paracentesis drainage for pleural effusion with a small or moderate volume on acute lung injury in patients with severe acute pancreatitis (SAP). Methods A retrospective analysis was performed for the clinical data of 107 patients with SAP who were admitted to The General Hospital of Western Theater Command from January 2015 to December 2021, and according to whether thoracic paracentesis drainage was performed within the first three days after admission, the patients were divided into thoracic paracentesis drainage group (TPD group with 51 patients) and non-thoracic paracentesis drainage group (N-TPD group with 56 patients).The two groups were compared in terms of laboratory markers and clinical outcome on days 5 and 10 after admission.The independent-samples t test was used for comparison of normally distributed continuous data between two groups, and the Mann-Whitney U test was used for comparison of non-normally distributed continuous data between two groups; the chi-square test was used for comparison of categorical data between two groups. Results Compared with the N-TPD group, the TPD group had a significantly shorter length of stay in the intensive care unit, a significantly shorter length of hospital stay, and significantly lower hospital costs (all P < 0.05), while there were no significant differences between the TPD group and the N-TPD group in mortality rate (9.8% vs 14.3%, χ 2 =0.502, P =0.478) and the incidence rate of sepsis (29.4% vs 44.6%, χ 2 =2.645, P =0.104).The TPD group had a significant reduction in the incidence rate of acute respiratory distress syndrome (ARDS)( χ 2 =6.038, P =0.043), as well as a significantly lower incidence rate of moderate ARDS than the N-TPD group (7.8% vs 21.4%, χ 2 =3.874, P =0.049).Compared with the N-TPD group, the TPD group had a significantly lower rate of use of mechanical ventilation (35.3% vs 57.2%, χ 2 =6.735, P =0.034) and a significantly lower proportion of patients receiving invasive mechanical ventilation (9.8% vs 26.8%, χ 2 =5.065, P =0.024).Compared with the N-TPD group, the TPD group had a significantly lower incidence rate of pulmonary infection (23.5% vs 42.9%, χ 2 =4.466, P =0.035) and a significantly shorter duration of systemic inflammatory response syndrome (11.2±5.0 days vs 16.8±4.7 days, t =5.949, P < 0.001).Compared with the N-TPD group, the TPD group had significantly better laboratory markers (high-sensitivity C-reactive protein, interleukin-1, interleukin-6, interleukin-8, tumor necrosis factor-α, arterial partial pressure of oxygen, oxygen saturation, and oxygenation index) and incidence rate of respiratory failure on days 5 and 10 after admission (all P < 0.05).On day 10 after admission, the TPD group had significantly better APACHE Ⅱ score and modified Mashall score than the N-TPD group (both P < 0.05). Conclusion For SAP patients with a small or moderate volume of pleural effusion, early thoracic paracentesis drainage can effectively improve acute lung injury, alleviate systemic inflammatory response, shorten the length of hospital stay, and reduce hospital costs.

Acute pancreatitis-associated ascites fluid (PAAF) is a common complication in patients with acute pancreatitis (AP) and is closely associated with the severity of AP, the development of local and systemic complications, and prognosis. PAAF may originate from the leakage of abdominal blood vessels, lymphatic vessels, and pancreatic duct. Recent studies have found that early removal of PAAF by abdominal paracentesis drainage can help to reduce systemic inflammation and alleviate pancreatitis-associated organ injury, thereby improving the conditions of patients with severe AP and reducing mortality. However, it is still not completely clear how PAAF aggravates systemic inflammatory response, participates in pancreatic injury and damage of distal organs, and leads to the aggravation of disease conditions in patients with AP. Therefore, this article gives an overview of PAAF and summarizes related studies in recent years, so as to provide directions for exploring the pathophysiological process and treatment of AP.

Objective To systematically analyze the World Health Organization Rehabilitation Competency Framework (RCF) theoretical framework, methodology and its application in the field of rehabilitation.Methods We systematically analyzed RCF conceptual framework and key characteristics, and discussed how to apply the RCF in the fields of human resource planning, education program and curriculum system, and vocational competency standards and certification criteria for rehabilitation human resources.Results The RCF encompasses five domains, naming practice, professionalism, learning and development, management and leadership, and research. Rehabilitation professionals' performance is the result of the interaction of their core values and beliefs, competencies, activities, knowledge, and skills. The RCF can be used to plan rehabilitation human resources, establish competency-based rehabilitation education programs and curriculum systems, and develop competency certification standards and licensure accreditation standards.Conclusion This study analyzed background, content and implementation framework of RCF, and systematically discussed the theories and methods related to how to use the RCF to construct national rehabilitation human resources development plans, develop rehabilitation education programs and curriculum systems based on the RCF, and establish certification and assessment standards for rehabilitation human resources.