Objective:To characterize the volatile compounds in 10 batches of disposable infusion sets and 6 batches of nasal can-nulas by GC-MS and determine the main odor-active compounds. Methods:The volatile components were extracted using a headspace sampler. An HP-5MS capillary column (30 m × 0. 25 mm,0. 25 μm) was adopted, and the qualitative analysis was performed by total ion chromatography ( TIC) of full scan with temperature programmer. Results:A total of 19 major volatile compounds were identified, which were hydrocarbon, alcohol and carbonyl compounds (such as aldehyde and ester). Based on the combination of odor test and GC-MS, the concentration of alcohol compounds (2-ethyl hexanol, 2-EH) had the most notable effect on the odor of samples. Conclu-sion:The samples with unacceptable order contain 2-EH with relatively high content, which should be paid more attention.

OBJECTIVETo investigate the effect of vacuum drainage on blood circulation of expanded skin flap, so as to confirm suitable negative pressure for ear reconstruction.

METHODS21 patients (Auricular Reconstructive Center of Plastic Surgery Hospital, PUMC) were randomly divided into A, B, C 3 groups to receive vacuum drainage of: -20, -40 and -60 kPa, respectively. The length and width of reconstructed ears,which represented the swelling degree, were measured instantly and 5, 10 days postoperatively. The changes were calculated and reflected venous drainage of flaps. The temperature of proximal (concha) and distal (helix) part of the expanded flaps, which represented the arterial blood supply of flaps, was detected by infrared thermography after operation.

RESULTSFive days after operation [(1.48 +/- 0.47) mm, (0.36 +/- 0.06) mm] and immediately [(1.67 +/- 0.69) mm, (0.40 +/- 0.16) mm)] , the changes of the length and width of reconstructed ear in group B was significantly low, while there was no statistically difference between group A and C (P > 0.05). The data between 10 days and 5 days after operation showed the same result. Along with the increase of the negative pressure, the swelling degree of reconstructed ears decreased firstly and then increased reversely ( P < 0.01 ). The flap temperature of reconstructed ears increased (P < 0.01), especially in proximal (concha) part (P < 0.01) , when the negative pressure increased (0 to -60 kPa).

CONCLUSIONSVacuum drainage has effect on both the venous drainage and blood supply. Negative pressure of -40 kPa can improve both the blood supply and venous drainage. It should be as reference for clinical application.

Child ; Ear Auricle ; surgery ; Female ; Humans ; Male ; Negative-Pressure Wound Therapy ; methods ; Reconstructive Surgical Procedures ; methods ; Ribs ; transplantation ; Skin Transplantation ; methods ; Surgical Flaps ; blood supply ; Transplantation, Autologous

Purpose To explore the consistency and clinical value of ultrasound and MRI in the diagnosis of giant cell tumor of tendon sheath(GCTTS)in extremities.Materials and Methods A retrospective analysis was performed on 35 patients who came to the First Affiliatted Hospital of Gannan Medical University from January 2020 to December 2022 due to hand-foot masses,and underwent ultrasound and MRI examination,which were confirmed by surgery or puncture cytology.Taking pathological results as the"gold standard",the sensitivity,specificity and positive likelihood ratio were compared,and the consistency and clinical value of the diagnostic classification of the two examination methods were further analyzed.Results Among the 35 cases of hand-foot masses,17 cases were diagnosed of GCTTS by ultrasound,16 cases were diagnosed of GCTTS by MRI,and 15 cases were diagnosed of GCTTS by pathologically.Ultrasound and MRI were consistent in the diagnostic classification of hand-foot masses in 30 cases and were inconsistent in diagnostic classification in 5 cases,and the diagnostic classification of the two mehtods was strongly consistent(Kappa=0.714).The sensitivity,specificity and coincidence rates of GCTTS in extremities diagnosed by ultrasound were 73.3%,70.0%and 71.4%,respectively.Those of GCTTS in extremities diagnosed by MRI were 80.0%,80.0%and 80.0%,respectively.Those of GCTTS in extremities diagnosed by ultrasound combined with MRI were 86.7%,70.0%and 77.1%,respectively.There were no significant differences in the diagnostic accuracy among ultrasound,MRI,ultrasound and MRI combined diagnosis and pathological examination(P>0.05).There were no significant differences in sensitivity,specificity,and positive likelihood ratio among ultrasound,MRI and the combined diagnosis of hand-and foot masses(P>0.05).Conclusion Ultrasound and MRI have good consistency in the classification and diagnosis of GCTTS in extremities.There was no significant difference between ultrasound and MRI in the overall diagnostic performance of GCTTS in extremities.