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1.
Biomed Mater ; 2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-32031987

RESUMO

Gelatin cryogels are good candidate scaffolds for tissue engineering benefiting from their interconnected macroporous structure. For bone regeneration, inorganic components are chosen to reinforce gelatin cryogels: i) to mimic the compositions of natural bone tissue, and ii) to meet the mechanical requirements of bone repairing. Cryogels were prepared from methacrylated gelatin (GelMA) in this study, and hydroxyapatite nanorods (HANRs) with surface-grafted acrylate groups (D-HANRs) were synthesized to reinforce the cryogels, in which, the crosslinking between GelMA and D-HANRs was expected. In parallel, HANRs and hydroxyapatite nanowires (HANWs) were also composited with the GelMA cryogels to investigate the effects of filler morphology and interfacial bonding on the overall properties of resulting composite cryogels comparatively. All these composite cryogels demonstrated potentials as bone repairing materials by displaying excellent performances such as high porosity, appropriate water retention, shape recovery and fast resilience features, as well as, good biocompatibility and cell affinity. In comparison with the HANRs composited GelMA cryogel, the HANWs were able to ameliorate the compression and the rheology performances of the resulting composite cryogels more efficiently due to the fact that the one-dimensional HANWs played a bridging role in the gelatin matrix. Among all the preparations, however, it was the D-HANRs achieving the strongest reinforcement efficiency in mechanical properties because the double bonds on their surface could be photocrosslinked with GelMA to form interfacial bonding. With these findings, it was summarized that inorganic fillers designed for cryogel-type bone repairing materials were preferred to be in one-dimensional morphology with surface functional groups to strengthen their interfacial bonding with the polymeric matrix.

2.
Biomed Res Int ; 2020: 1360843, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32025515

RESUMO

Diabetic nephropathy (DN) is characterized by metabolic disorder and inflammation. However, the regulatory effects that long noncoding RNAs (lncRNAs) have on the pathogenesis of DN and on the efficacy of rosiglitazone treatment have yet to be clearly defined. Herein, we performed unbiased RNA sequencing to characterize the transcriptomic profiles in db/db diabetic mouse model with or without rosiglitazone treatment that served to improve the phenotypes of DN. Moreover, RNA-seq profiling revealed that the development of DN caused an upregulation in the expression of 1176 mRNAs and a downregulation in the expression of 1010 mRNAs compared to controls, with the expression of 251 mRNAs being returned to normal following treatment with rosiglitazone. Further, 88 upregulated and 68 downregulated lncRNAs were identified in db/db mice compared to controls, 10 of which had their normal expression restored following treatment with rosiglitazone. Bioinformatic analysis revealed that the primary pathways involved in the pathogenesis of DN, and subsequently in the therapeutic effects of PPARγ, are related to inflammatory and metabolic processes. From bioinformatics analysis, lncRNA-AI838599 emerged as a novel molecular mechanism for rosiglitazone treatment in DN through TNFα-NFκb pathway. These findings may indicate a new molecular regulatory approach for the development of DN therapeutic agents.

3.
Acupunct Med ; : 964528419900911, 2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-32028783

RESUMO

BACKGROUND: Evidence for treating postprandial distress syndrome with acupuncture is limited. AIM: We aimed to evaluate the feasibility of verum acupuncture versus sham acupuncture in patients with postprandial distress syndrome. METHODS: A total of 42 eligible patients were randomly allocated to either verum acupuncture or sham acupuncture groups in a 1:1 ratio. Each patient received 12 sessions over 4 weeks. The primary outcome was the response rate based on the overall treatment effect (OTE) 4 weeks after randomization. Secondary outcomes included dyspepsia symptom severity and adverse events. RESULTS: In each group, 19 patients (91.5%) completed the study. Thirteen patients receiving verum acupuncture and seven patients receiving sham acupuncture were classified as responders according to OTE (61.9% vs 33.3%; rate difference 28.6%; p = 0.06). Dyspepsia symptom severity at the end of treatment also differed significantly between verum acupuncture and sham acupuncture groups (5.9 units vs 3.7 units; between-group difference 2.2 (95% CI, 0.2-4.2); p = 0.04). No serious adverse events occurred. CONCLUSION: Four weeks of acupuncture may represent a potential treatment for postprandial distress syndrome. The treatment protocol and outcome measures used in this trial were feasible. Since this was a pilot study, the efficacy of acupuncture still needs to be determined by a larger, adequately powered trial.

4.
Artigo em Inglês | MEDLINE | ID: mdl-32029274

RESUMO

Colorectal cancer (CRC) is the third most commonly malignancy worldwide. The incidence of CRC is on the rise and leads to indisputable society burden due to the high cost of cancer treatments. Resistance to oxaliplatin-chemotherapy is the major cause for treatment failure and CRC-related death. In this study, we anticipated that TXNDC9 might demonstrate a protective role in oxaliplatin-resistant CRC cells. TXNDC9 was found significantly upregulated when treated with oxaliplatin. Manipulation of TXNDC9 expression largely affected the oxaliplatin-induced cell death. Moreover, TXNDC9 regulates autophagy and apoptosis in response to oxaliplatin treatment in HT29 cells via the Nrf2 pathway. Taken together, our findings explore the biological role of TXNDC9 in oxaliplatin resistance in CRC cells and may identify a novel therapeutic target to counteract drug resistance to oxaliplatin in CRC.

5.
Breast Cancer ; 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-32040723

RESUMO

BACKGROUND: The burden of breast cancer has grown rapidly in China during recent decades. However, the association between tumor markers (CA15-3, CA125, and CEA) and breast cancer survival among certain molecular subtypes is unclear; we described this association in a large, population-based study. METHODS: We conducted a cohort study including 10,836 women according to the Tianjin Breast Cancer Cases Cohort. Demographic and epidemiologic data were collected by a structured face-to-face questionnaire. Clinico-pathological parameters were abstracted from medical records, and follow-up information was obtained once a year by telephone. The primary endpoints were breast cancer-specific survival (BCSS) and disease-free survival (DFS). We utilized the Cox proportional hazard model to calculate hazard ratios (HRs) and 95% confidence intervals (CI). RESULTS: Among all patients, elevated CA15-3 and CEA exhibited consistently and statistically significant reduced BCSS compared with normal ones (CA15-3: HR 1.54, 95% CI 1.01-2.34; CEA: HR 2.45, 95% CI 1.40-4.30). Similar patterns of association were observed for DFS (CA15-3: HR 2.09, 95% CI 1.44-3.02; CEA: HR 2.71, 95% CI 1.71-4.27). Moreover, in luminal A subtype, high CA15-3 and CEA levels were associated with decreased BCSS (CA15-3: HR 4.47, 95% CI 2.04-9.81; CEA: HR 3.79, 95% CI 1.68-8.55) and DFS (CA15-3: HR 4.06, 95% CI 2.29-7.18, CEA: HR 3.41, 95% CI 1.75-6.64). In basal-like subtype, elevated CEA conferred reduction for BCSS (HR 5.13, 95% CI 1.65-15.9). However, no association was observed between CA125 and breast cancer outcome. CONCLUSIONS: Preoperative CA15-3 and CEA levels differ in breast cancer molecular subtypes and yield strong prognostic information in Chinese women with breast cancer. Measuring CA15-3 and CEA levels before surgery may have the potential in predicting breast cancer survival and offering patients' personalized treatment strategy among luminal A and basal-like subtypes.

6.
Arch Dermatol Res ; 2020 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-31953572

RESUMO

TL1A, as a master regulatory cytokine, plays a key role in the development of diverse T-cell-mediated inflammatory and autoimmune diseases. Our study is to further understand the roles of TL1A in the pathogenic mechanism of psoriasis and to find a possible new therapeutic strategy in the treatment of psoriasis. The direct effects of TL1A injection in mice skin and the therapeutic effects of TL1A blockade in imiquimod (IMQ)-induced psoriasis-like mouse model were researched in this study. First, we found that the expressions of TL1A in IMQ-treated lesions were significantly higher than Vaseline control group. And then, the results showed that TL1A injection exacerbated the psoriasiform phenotype on IMQ-treated skin (including clinical score, epidermal thickness changes, and Baker score) by increasing the number of T cells, neutrophils, and DCs, and upregulating the mRNA expression of IFN-γ and IL-17. However, anti-TL1A mAb can alleviate psoriasis-like lesions in clinical and effectively improved the histopathologic changes in IMQ-induced psoriasis-like mice after treatment. Moreover, anti-TL1A mAb also reduced the number of infiltrated CD3+ T cells, MPO+ neutrophils, and CD11c+ DCs in psoriasis-like lesions, and obviously decreased the expression of IFN-γ and IL-17 in psoriasis-like lesions. Data suggested that TL1A might be involved in the pathogenesis of psoriasis, and targeting TL1A by anti-TL1A mAb might provide a solid foundation and novel therapeutic sight in the treatment of psoriasis.

8.
Br J Radiol ; : 20190558, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31957473

RESUMO

OBJECTIVE: To build and validate a CT radiomic model for pre-operatively predicting lymph node metastasis in early cervical carcinoma. METHODS AND MATERIALS: A data set of 150 patients with Stage IB1 to IIA2 cervical carcinoma was retrospectively collected from the Nanfang hospital and separated into a training cohort (n = 104) and test cohort (n = 46). A total of 348 radiomic features were extracted from the delay phase of CT images. Mann-Whitney U test, recursive feature elimination, and backward elimination were used to select key radiomic features. Ridge logistics regression was used to build a radiomic model for prediction of lymph node metastasis (LNM) status by combining radiomic and clinical features. The area under the receiver operating characteristic curve (AUC) and κ test were applied to verify the model. RESULTS: Two radiomic features from delay phase CT images and one clinical feature were associated with LNM status: log-sigma-2-0 mm-3D_glcm_Idn (p = 0.01937), wavelet-HL_firstorder_Median (p = 0.03592), and Stage IB (p = 0.03608). Radiomic model was built consisting of the three features, and the AUCs were 0.80 (95% confidence interval: 0.70 ~ 0.90) and 0.75 (95% confidence intervalI: 0.53 ~ 0.93) in training and test cohorts, respectively. The κ coefficient was 0.84, showing excellent consistency. CONCLUSION: A non-invasive radiomic model, combining two radiomic features and a International Federation of Gynecology and Obstetrics stage, was built for prediction of LNM status in early cervical carcinoma. This model could serve as a pre-operative tool. ADVANCES IN KNOWLEDGE: A noninvasive CT radiomic model, combining two radiomic features and the International Federation of Gynecology and Obstetrics stage, was built for prediction of LNM status in early cervical carcinoma.

9.
Ying Yong Sheng Tai Xue Bao ; 31(1): 319-325, 2020 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-31957410

RESUMO

Investigating the composition of food sources with stable isotope method can provide direct evidence for the top-down control in the coastal wetland. In this study, we examined food source and feeding habit of Helice tientsinensis of common reed (Phragmites australis) vegetation in high marsh of Yellow River Delta. The results showed that the density of crab was (5.5±1.5) ind·m-2, with the behavior of climbing P. australis to feed on the leaves at night. Under the same indoor experimental condition, H. tientsinensis showed feeding preference on fresh leaves of P. aus-tralis. The stable isotope food source analysis showed that the leaves of P. australis were one of the important food sources of H. tientsinensis in the field. There were temporal variations in the proportion of fresh leaves [May: (6.4±4.9)%, July: (5.8±4.9)%, September: (12.5±8.8)%] and dead leaves [May: (12.4±7.8)%, July: (15.5±9.9)%, September: (15.1±9.4)%]. Therefore, H. tientsinensis could inhibit P. australis's growth and affect litter decomposition through feeding disturbance behavior.


Assuntos
Braquiúros , Áreas Alagadas , Animais , China , Hábitos , Poaceae , Rios
10.
J Exp Med ; 217(4)2020 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-31999304

RESUMO

Aberrant NLRP3 inflammasome activation contributes to the development of endotoxemia. The importance of negative regulation of NLRP3 inflammasomes remains poorly understood. Here, we show that the E3 ubiquitin ligase Cbl-b is essential for preventing endotoxemia induced by a sub-lethal dose of LPS via a caspase-11/NLRP3-dependent manner. Further studies show that NLRP3 undergoes both K63- and K48-linked polyubiquitination. Cbl-b binds to the K63-ubiquitin chains attached to the NLRP3 leucine-rich repeat domain (LRR) via its ubiquitin-associated region (UBA) and then targets NLRP3 at K496 for K48-linked ubiquitination and proteasome-mediated degradation. We also identify RNF125 as an additional E3 ubiquitin ligase that initiates K63-linked ubiquitination of the NLRP3 LRR domain. Therefore, NLRP3 is sequentially ubiquitinated by K63- and K48-linked ubiquitination, thus keeping the NLRP3 inflammasomes in check and restraining endotoxemia.

11.
Med Sci Monit ; 26: e918174, 2020 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-31957742

RESUMO

BACKGROUND The aim of this study was to explore the expression of miR-140 and miR-199 in synovia of patients with knee osteoarthritis (KOA) and its correlation with the progression of this disease. We used the Kellgren and Lawrence grading (KLG) system. MATERIAL AND METHODS There were 110 patients with early (KLG <2), middle (KLG=2) and late (KLG >2) stage KOA and 60 healthy individuals (control) included in this study. RESULTS The relative expression levels of miR-140 (1.07±0.091) and miR-199 (1.03±0.110) in synovia of the control group were higher than those of KOA groups (0.511±0.130, 0.298±0.168) and the difference exhibited statistical significance (P<0.01). Expression of miR-140 in the middle and the late stage KOA groups (0.322±0.118 and 0.110±0.088 respectively) were 58.80% and 81.29% lower, respectively, compared to the early stage KOA group (0.588±0.172), which was significant (P<0.05). Expression of miR-199 in the middle and the late stage KOA groups (0.210±0.124 and 0.056±0.068 respectively) were 39.41% (P<0.05) and 83.72% (P<0.01) respectively lower than that in the early KOA group (0.344±0.147). The severity of OA was significantly negatively correlated with the expressions of miR-140 and miR-199 (r=-0.859, P<0.05; r=-0.724, P<0.001 respectively). Matrix metalloproteinase (MMP)-3 levels of the early stage, middle stage and late stage KOA groups were 1.320±0.118, 1.488±0.210, and 1.955±0.023 respectively; and IL-1ß mRNA was 1.401±0.204, 1.522±0.210, and 1.889±0.217 respectively, which were obviously higher than those in the control group (1.020±0.085), (P<0.05). CONCLUSIONS Expression levels of miR-140 and miR-199 in synovia might act as an early diagnostic marker for KOA. These expression levels might also act as indicators of OA progression to some extent.

12.
Hum Brain Mapp ; 2020 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-31944479

RESUMO

Hippocampal atrophy and abnormal ß-Amyloid (Aß) deposition are established markers of Alzheimer's disease (AD). Nonetheless, longitudinal trajectory of Aß-associated hippocampal subfield atrophy prior to dementia remains unclear. We hypothesized that elevated Aß correlated with longitudinal subfield atrophy selectively in no cognitive impairment (NCI), spreading to other subfields in mild cognitive impairment (MCI). We analyzed data from two independent longitudinal cohorts of nondemented elderly, including global PET-Aß in AD-vulnerable cortical regions and longitudinal subfield volumes quantified with a novel auto-segmentation method (FreeSurfer v.6.0). Moreover, we investigated associations of Aß-related progressive subfield atrophy with memory decline. Across both datasets, we found a converging pattern that higher Aß correlated with faster CA1 volume decline in NCI. This pattern spread to other hippocampal subfields in MCI group, correlating with memory decline. Our results for the first time suggest a longitudinal focal-to-widespread trajectory of Aß-associated hippocampal subfield atrophy over disease progression in nondemented elderly.

13.
J Hazard Mater ; 389: 122083, 2020 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-31972523

RESUMO

Occurrence, distribution, and ecological risk of 21 pharmaceuticals in the Jilin Songhua River were investigated during its freeze-thaw periods, including ice formation, sealed, and breakup. Florfenicol was the most abundant pharmaceutical, with mean concentrations of 123.4 ± 61.1 ng L-1 in water and 73.8 ± 66.3 ng kg-1 in ice. Sulfadiazine occurred at a higher mean concentration in downstream areas (45.6 ± 7.4 ng L-1) than in upstream areas (0.7 ± 0.7 ng L-1). Most pharmaceuticals appeared in relatively high concentrations in water during the ice-breakup period. Complex factors including pharmaceutical usage patterns, ice-regulated photodegradation, biodegradation, water flow, and freeze-concentration effects, as well as the release of pharmaceuticals from ice, were responsible for the temporal variation of pharmaceuticals. Pseudo-ice/water distribution coefficients showed the distribution of pharmaceuticals in ice and demonstrated the effects of their release from the ice on their temporal variations. Most pharmaceuticals posed a risk to algae; of these, amoxicillin exhibited the highest risk. In addition, thawing increased the concentration of thiamphenicol in water, which elevated its ecological risk level. The findings suggest that the pharmaceuticals retained in ice should be considered with regard to regulating pharmaceuticals' temporal variations in seasonal ice-covered rivers during the freeze-thaw process.

14.
J Cell Mol Med ; 24(3): 2215-2228, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31943775

RESUMO

Increasing evidence has verified that small nucleolar RNAs (snoRNAs) play significant roles in tumorigenesis and exhibit prognostic value in clinical practice. In the study, we analysed the expression profile and clinical relevance of snoRNAs from TCGA database including 530 ccRCC (clear cell renal cell carcinoma) and 72 control cases. By using univariate and multivariate Cox analysis, we established a six-snoRNA signature and divided patients into high-risk or low-risk groups. We found patients in high-risk group had significantly shorter overall survival and recurrence-free survival than those in low-risk group in test series, validation series and entire series by Kaplan-Meier analysis. We also confirmed this signature had a great accuracy and specificity in 64 clinical tissue cases and 50 serum samples. Then, depending on receiver operating characteristic curve analysis we found the six-snoRNA signature was an superior indicator better than conventional clinical factors (AUC = 0.732). Furthermore, combining the signature with TNM stage or Fuhrman grade were the optimal indicators (AUC = 0.792; AUC = 0.800) and processed the clinical applied value for ccRCC. Finally, we found the SNORA70B and its hose gene USP34 might directly regulate Wnt signalling pathway to promote tumorigenesis in ccRCC. In general, our study established a six-snoRNA signature as an independent and superior diagnosis and prognosis indicator for ccRCC.

16.
J Cell Biochem ; 121(2): 1901-1910, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31633244

RESUMO

PURPOSE: The aim of this study was to screen survival-related genes for glioblastoma (GBM). METHODS: GSE53733 was downloaded from Gene Expression Omnibus (GEO) database, including 16 short-term (ST), 31 intermediate (IM), and 23 long-term (LT) survivors. Analysis of variance was used to analyze the expression in three groups. The genes with P < .01 were screened as differentially expressed genes (DEGs). Soft clustering was performed using Mfuzz to mine the expression patterns of differential genes in three groups of overall survival (OS) classification. The cytoscape plugin clueGO was used for functional enrichment analysis. The protein interaction between differential genes was extracted from the STRING V10 database, and the protein-protein interaction (PPI) network was constructed and displayed with cytoscape. The hub genes were verified by quantitative reverse-transcription polymerase chain reaction. RESULTS: Total 662 DEGs were obtained among three groups and enriched in 12 clusters. The overlap analysis between clusters could classify these 12 clusters Cluster A and B. Total 264 OS.DEGs were contained in Cluter A and Cluster B, and enriched in 28 Gene Ontology terms, such as trophoblast giant cell differentiation (P value = 6.18E-04), muscle fiber development (P value = 9.09E-04), and negative regulation of stem cell differentiation (P value = 1.76E-03). The top five nodes with highest degree in OS.PPI were HDAC1, DECR1, RASL11A, PDIA3, and POLR2F. The expression of DECR1 and POLR2F was significantly lower, while the levels of HDAC1 and PDIA3 were highly expressed in GBM tissues. CONCLUSION: DECR1, POLR2F, HDAC1, and PDIA3 might be potential key genes affected the overall survival time of patients with GBM.

17.
J Cell Biochem ; 121(2): 1842-1854, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31633246

RESUMO

Gastric cancer (GC) is one of the most fatal common cancers in worldwide. Helicobacter pylori (H. pylori) infection is closely related to the development of GC, although the mechanism is still unclear. In our study, we aim to develop a robust messenger RNA (mRNA) signature associated with H. pylori (-) GC that can sensitively and efficiently predict the prognostic. The RNA-seq expression profile and corresponding clinical data of 598 gastric cancer samples and 63 normal samples obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus database. Using gene set enrichment analysis H. pylori (+) GC and H. pylori (-) GC patients and normal samples to select certain genes for further analysis. Using univariate and multivariate Cox regression model to establish a gene signature for predicting the overall survival (OS). Finally, we identified G2/M related seven-mRNA signature (TGFB1, EGF, MKI67, ILF3, INCENP, TNPO2, and CHAF1A) closely related to the prognosis of patients with H. pylori (-) GC. The seven-mRNA signature was identified to act as an independent prognostic biomarker by stratified analysis and multivariate Cox regression analysis. It was also validated on two test groups from TCGA and GSE15460 and shown that patients with high-risk scores based on the expression of the seven mRNAs had significantly shorter survival times compared to patients with low-risk scores (P < .0001). In this study, we developed a seven-mRNA signature related to G2/M checkpoint from H. pylori (-) GCs that as an independent biomarker potentially with a good performance in predicting OS and might be valuable for the clinical management for patients with GC.

18.
J Biomech ; 99: 109482, 2020 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-31733820

RESUMO

Hamstring muscle strain injury is one of the most common injuries in sports involving sprinting and kicking. Studies examining hamstring kinematics and activations are rich for sprinting but lacking for kicking. The purpose of this study was to examine kinematics and activations of hamstring muscles in instep and cut-off kicking tasks frequently performed in soccer. Videographic and electromyographic (EMG) data were collected for 11 male soccer-majored college students performing the two kicking tasks. Peak hamstring muscle-tendon unit lengths, elongation velocities, and maximum linear envelop EMG data were identified and compared among hamstring muscles and between kicking tasks. Hamstring muscles exhibited activated elongations before and after the contact of the kicking foot with the ball. The muscle-tendon unit lengths peaked in the follow-through phase. The peak elongation velocity of the semimembranosus was significantly greater than that of the semitendinosus and biceps femoris (p = 0.001). The maximum linear envelop EMG of the biceps femoris was significantly greater than that of the semimembranosus (p = 0.026). The potential for hamstring injury exists in the follow-through phase of each kicking task. The increased hamstring muscle-tendon unit elongation velocities in kicking tasks may explain the more severe hamstring injuries in kicking compared to sprinting.

19.
Eur J Dermatol ; 29(5): 577-578, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31789288
20.
ACS Appl Mater Interfaces ; 11(51): 48505-48511, 2019 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-31790580

RESUMO

The unidirectional liquid spreading without external energy input has presently aroused widespread concern. Recently, on the peristome of Nepenthes alata, a novel 2D unidirectional liquid spreading has been reported. It has been revealed that its exquisite superhydrophilic multistage microstructure, overlapping microcavities with arc-shaped edges and wedge-shaped corners, is the main reason for this phenomenon. To fabricate a peristome-inspired surface, a replica molding method is highly efficient and provides an ideal structure. However, the curved shape of the finally formed surface cannot be adjusted, and a specific surface shows only one type of liquid spreading state, greatly limiting its potential application. Here, we aimed to develop a novel surface-tension-assisted replica molding method to fabricate an artificial peristome film. The artificial peristome film was fabricated by pouring styrenic block copolymers (SBS) dissolved in organic solvents into a negative replica prepared in polydimethylsiloxane (PDMS), based on the natural peristome. With volatilizing the organic solvent, the SBS agglomerates formed an artificial peristome film via surface tension effects. More importantly, the PDMS-negative replica swelled in the organic solvent and then returned to the original size, which is conducive for replicating microstructures. The liquid spreading speed could be dynamically controlled by stretching the artificial peristome film. We demonstrated that the microcavity wedge angle decreases with an increasing stretching ratio. A smaller wedge angle can result in a much stronger unidirectional liquid spreading ability. This study provides insight into the dynamic control of unidirectional liquid spreading for novel pump-free medical microfluidic devices.

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