In this paper,the classification,application and advantages of three-dimensional (3D) printing in biomedical engineering are summarized.The working principles of 3D printing,stereolithography,fused deposition modeling,selective laser sintering and 3D spray printing,as well as merits,demerits and recent progress are reviewed.The 3D printing has been widely used in the synthetic of bone tissue engineering scaffolds,with biodegradable and bioactive materials in the scaffold.Synthetic bone materials and surgical simulation by 3D printing technology are increasingly common and has achieved satisfactory results in China.Although 3D printing technology has developed rapidly,development of suitable biomaterials and improving relevant techniques are still urgent issues.Up to now,the functionalization of bionic organs is the most difficult issue,in which the cell co-culture,vascularization and preparation of the scaffolds are problem to be solved.The 3D printing technology will make remarkable achievements for the regeneration and repair of human organ through our efforts.

Objective To study the influence factor of recurrence in breast cancer.Methods The grouping treatment and tumor by stages,tumor transfer were observed in 105 cases with primary breast cancer.Results Among 105 patients,the inside of 2 years relapse was 47.6%(50/105);Tumor Ⅱ period recurrence rate was 40.0%(10/25),Ⅲ period recurrence rate was 28.0%(7/25);Among 105 cases,the distant place transfer to recurrence rate was 31.4%(33/105);Among 105 patients for surgical operation,its relapsing rate was 40.0%,but in 25 cases after operation putting radiation treatment,relapse rate was 16.0%;The part recurrence rate totally was 58.0%(61/105),among them the chest wall recurrence rate was 13.3%(14/105);The supraclavilar lymphonodes transfer was 20.9%(22/105),the axlla lymphnides transfer was 23.8%(25/105);The distant place transfer was 31.4%(33/105).Conclusion The recurrence rate of association treatment obviously is lower than that pure surgical operation,the relapsing of tumor with tumor by stages and transfer relevanted.

Objective To explore the effrciency of intra-arterial neoadjuvant chemotherapy before radical excision in patients with cervical cancer.Methods 50 cases with cervical cancer were enrolled into the study and were treated with a 2～3 course of intra-arterial neoadjuvant chemotherapy immediately after the pathological diagnosis.The regime included Then radical excision was performed in those who were good for the operation.Results Complete recovery(CR) was acquired in 12 patients and partial recovery(PR) in 26 patients.The total response rate was 76.0 %.The tumor size reduced significantly(P

Polyamidoamine-polyethylene glycol (PAMAM-PEG) copolymers were synthesized using IPDI as coupling reagent by two-step method. The copolymers were characterized by IR spectrum and 1H NMR spectrum, and the PEG conjugating ratios of the copolymers were calculated equal to 10% and 30% separately. MTT assay indicated that after PEGylation a lower cytotoxicity of the copolymers could be found, and with increasing PEG conjugating ratio the cytotoxicity decreased obviously. Agarose gel retardation assay demonstrated that PAMAM-PEG copolymers could be combined with DNA and PAMAM-PEG/DNA complexes were prepared by self-assembly. DLS measurement showed that when N/P > or = 50, the particle size of copolymer/ gene complexes was in a range of 150-200 nm, and the zeta potential was in a range of 10-25 mV. In vitro gene transfection illustrated that when N/P < or = 50, the gene transfection efficiency of PAMAM-PEG copolymers was a little less than that of PAMAM-G5, but the transfection efficiency can be raised by increasing N/P ratio or transfection time. Considering both cytotoxicity and transfection efficiency aspects PAMAM-PEG-13 was more effect than PAMAM-PEG-39 in PEGylation.

Ambulatory Care Facilities ; Humans ; Mental Disorders ; diagnosis ; Occupational Medicine ; Referral and Consultation ; Symptom Assessment

Objective:To study the effects of ascorbic acid on BMP-2 mRNA expression of osteoblast cell sheets.Methods:Rat os-teoblasts were primaryly cultured and identified;osteoblast cell sheets were built by physical scraping method in vitro;the osteoblast cell sheets were cultured with 1 5,50 and 85 mg/L ascorbic acid for 1 and 2 weeks respectively,and the expression of BMP-2 mRNA of the cell sheets was detected by RT-qPCR.Results:The obtained cells were conformed to be osteoblasts.The osteoblast cell sheets could be rolled into tube in vitro.The expression of BMP-2 mRNA of osteoblast cell sheets in experiment group,whether in week one or week two was higher than that in control group,50 mg/L group showed the highest expression(first week P <0.05;second week P>0.05);the expression of any group in week two was higher than that in week one(P <0.05).Conclusion:Ascorbic acid may pro-mote the expression of BMP-2 mRNA in osteoblast cell sheets.

Objective:To investigate the success rate, operation time and complications of ultrasound combined with X-ray-guided precise implantation of totally implantable access port (TIAP) in the chest wall.Methods:A total of 623 patients who underwent implantation of totally implantable venous access ports in the chest wall in Meizhou People's Hospital, China between January 2015 and August 2018 were included in this study. In group A ( n = 320), jugular or subclavian access ports were precisely implanted in the chest wall under the guidance of ultrasound combined with X-ray. During the surgery, color Doppler ultrasound was used to guide the puncture and a C-arm machine was used to locate the position of catheter tip. In group B ( n = 303), venous access ports were implanted using the conventional method. Subclavian vein puncture was performed using anatomic landmarks and the depth of catheterization was estimated by experience. The success rate of the first implantation, operation time, and complications (pneumothorax, hemothorax, catheter displacement, poor position of catheter tip, skin infection, and thrombosis) were compared between the two groups. Results:There were no statistical differences in baseline data between the two groups ( P > 0.05). The success rate of the first implantation in the group A was significantly higher than that in the group B [100% (320/320) vs. 93.06% (282/303), χ2 = 22.95, P < 0.01]. The operation time in the group A was significantly shorter than that in the group B [(26.48 ± 5.49) minutes vs. (35.51 ± 14.37) minutes, t = -10.25, P < 0.01]. In group A, 2 patients developed pneumothorax and healed after conservative treatment, 6 patients had thrombosis, and the incidence of complications was 2.5% (8/320). In group B, complications occurred in 67 patients, including pneumothorax in 9 patients, poor catheter tip position in 17 patients, thrombosis in 36 patients, and skin infection in 1 patient, and the incidence of complications was 22.11% (67/303). There was significant difference in the incidence of complications between the two groups ( χ2 = 56.53, P < 0.01). In group B, 6 out of 9 patients developing pneumothorax were healed after closed thoracic drainage, and 4 patients underwent a secondary surgery because of catheter displacement into the internal jugular vein. Conclusion:Precise implantation of venous access ports in the chest wall guided by ultrasound combined with X-ray has the advantages including 100% success rate of first precise implantation, few complications, short operation time, high comfort, safety and efficacy.

Objective To study the effect of pirfenidone (PFD) on the transformation of rat corneal stromal cells into fibroblasts in vitro and further explore the anti-fibrotic effect of PFD. Methods The corneal stromal cells from SD rat was isolated and cultured ,and was determined by vimentin stain. The experiment was divided into control group(DMEM+10%FBS),TGF-β1 group(2 ng/mL TGF-β1+DMEM+10%FBS)and PFD group(1 mg/mL PFD+ 2 ng/mL TGF-β1+DMEM+ 10%FBS). Cell proliferation was detected by CCK-8 assay. Collagen Ⅰ,Collagen Ⅲ,Keratocan and CD99 expression were detected by Western blot. Results Compared with control group and TGF-β1 group,the cell proliferation were significantly decreased in PFD group(P<0.05). Western blot showed that PFD can up-regulated Collagen Ⅰand Keratocan but down-regulated Collagen ⅢCD90 expression(P < 0.05). The ratio of Collagen Ⅲ/Collagen Ⅰ in PFD group was lowest in all groups(P < 0.05). Conclusion PFD can resistant fibration in corneal stromal cells may through the inhibition of TGF-β ,which affect the collagen synthesis and Keratocan,CD90 expression.

Objective To study the influence of patient perceived medical service quality on the satisfaction and behavioral intention.Methods The AMOS21.0 software was adopted to construct a structural equation model with satisfaction as a medium for conducting the path analysis among the perceived medical service quality,satisfaction and behavioral intention.Results The perceived medical service quality produced the direct impact on behavioral intention(y=0.50) and satisfaction(γ=0.87),the satisfaction produced the direct impact on behavioral intention(γ=0.38);with the satisfaction as a medium,the perceived medical service quality had the indirect impact(0.33) on behavioral intention and the intermediary rate was 39.76％.Conclusion The perceived medical service quality has active influence on the patient satisfaction and behavior intention,and indirectly acts on the behavioral intention with the satisfaction as intermediary agent.

Objective To evaluate the in vitro effects of photodynamic therapy alone or in combination with antifungal agents on the apoptosis of planktonic and biofilm cells of Exophiala dermatitidis (E.dermatitidis).Methods The planktonic suspensions of E.dermatitidis were prepared,and the biofilms of E.dermatitidis were prepared via a modified 96-well plate-based methods.Planktonic and biofilm cells of E.dermatitidis were separately divided into several groups:antifungal agent groups treated with antifungal agents alone,photodynamic therapy group receiving photodynamic therapy alone,combination groups receiving photodynamic therapy followed by the treatment with antifungal agents,and blank control group receiving no treatment.These antifungal agents included amphotericin B,posaconazole,voriconazole and itraconazole.The concentrations of these antifungal agents were all 1 mg/L,and the treatment with antifungal agents lasted 2 hours.Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay was performed to detect the apoptosis of planktonic and biofilm cells of E.dermatitidis in all the groups.Results The antifungal agents and photodynamic therapy both affected the apoptosis of planktonic (both P ＜ 0.001) and biofilm cells (beth P ＜ 0.05) of E.dermatitidis.The apoptosis rates of E.dermatitidis planktonic cells in the control group,amphotericin B group,posaconazole group,voriconazole group and itraconazole group were 11.67％ ± 0.21％,13.30％ ± 1.78％,14.30％ ± 3.61％,14.51％ ± 1.91％and 36.17％ ± 4.00％ respectively.The apoptosis rate of E.dermatitidis planktonic cells was significantly higher in the itraconazole group than in the control group (P ＜ 0.05),but no significant differences were observed between the other 3 antifungal agent groups and control group (all P ＞ 0.05).The photodynamic therapy group also showed a significantly higher apoptosis rate of E.dermatitidis planktonic cells (41.37％ ±7.80％) compared with the control group (P ＜ 0.05).After the treatment with photodynamic therapy combined with amphotericin B,posaconazole,voriconazole or itraconazole,the apoptosis rates of E.dermatitidis planktonic cells were 29.23％ ± 6.71％,37.23％ ± 10.86％,43.57％ ± 6.42％ and 69.87％ ± 3.53％ respectively.Moreover,the photodynamic therapy + voriconazole group and photodynamic therapy + itraconazole group both showed significantly higher apoptosis rates compared with the voriconazole group and itraconazole group respectively (both P ＜ 0.05).The apoptosis rate of E.dermatitidis biofilm cells was significantly higher in the photodynamic therapy group than in the control group (32.00％ ± 0.43％ vs.25.30％ ± 1.31％,P ＜ 0.05),as well as in the photodynamic therapy + amphotericin B than in the amphotericin B group (P ＜ 0.05).Conclusion Photodynamic therapy combined with antifungal agents can markedly promote the apoptosis of planktonic and biofilm cells of E.dermatitidis.