Biomimetic materials have emerged as attractive and competitive alternatives for tissue engineering (TE) and regenerative medicine. In contrast to conventional biomaterials or synthetic materials, ...biomimetic scaffolds based on natural biomaterial can offer cells a broad spectrum of biochemical and biophysical cues that mimic the in vivo extracellular matrix (ECM). Additionally, such materials have mechanical adaptability, microstructure interconnectivity, and inherent bioactivity, making them ideal for the design of living implants for specific applications in TE and regenerative medicine. This paper provides an overview for recent progress of biomimetic natural biomaterials (BNBMs), including advances in their preparation, functionality, potential applications and future challenges. We highlight recent advances in the fabrication of BNBMs and outline general strategies for functionalizing and tailoring the BNBMs with various biological and physicochemical characteristics of native ECM. Moreover, we offer an overview of recent key advances in the functionalization and applications of versatile BNBMs for TE applications. Finally, we conclude by offering our perspective on open challenges and future developments in this rapidly-evolving field.
The exploration of turn-on fluorescent method for sensitive detection of tetracycline is still challenging. This paper reports a kind of specific structure of self-assembled copper nanoclusters ...(CuNCs), greatly enhancing the fluorescence emission intensity of tetracycline (TC). Fluorescence enhancement is mainly ascribed to that tetracycline can defuse into the compatible space of special structure of self-assembled CuNCs, and intramolecular motion of TC can be effectively restricted, leading to fluorescence emission enhancement of TC. The assay enables TC to be detected with high sensitivity and linear response that covers the 200 nM to 50 μM TC concentration range with a 40 nM limit of detection, which is lower by 50-fold than the method without self-assembled CuNCs. Furthermore, the strategy is further applied for determining TC contents in milk and urine samples.
A novel fluorescent strategy has been developed for the sensitive detection of tetracycline based on the specific structure of self-assembled CuNCs and the restriction intramolecular motion. Display omitted
•A novel strategy has been exploited for the improvement of the fluorescence signal of tetracyclines through RIM.•The special structure of self-assembled CuNCs can offer a more beneficial microenvironment for fluorescence enhancing.•The LOD for TC assay was lower by 50-fold than the method without 4CH3-CuNCs.•The method was simple and cost-effective, and performed within several minutes at room temperature.•This strategy was free of any fluorescence dye label and other complex design.
The teeth of planetary gear trains are prone to wear and can be damaged. In traditional wear monitoring, the equipment needs to be disassembled, and the efficiency is low. The wear debris in ...lubricating oil can provide information about machine wear. On-line oil monitoring technology can easily recognize the change of wear debris concentration in the gearbox oil pan without the need for disassembling equipment. However, existing on-line monitoring systems are often based on wear debris concentration, providing limited information on particle shape and type, which are important for root cause analysis. In this study, some new features of wear debris were extracted for on-line wear monitoring in order to improve wear state evaluation and prediction using on-line approach.
•The new algorithms can realize the on-line wear debris monitoring images denoising and wear information extraction.•Several new indicators of wear debris chains can be used to analyze the shape and concentration of wear debris.•The new factor can be used to estimate the distribution of indicators accurately and evaluate the wear state quickly.•Gear box wear tests and on-line wear debris analysis was conducted to evaluate the performances of new methods.
Abstract
Introduction
Sliding compression fixation and length-stable fixation are two basic internal fixation concepts in the treatment of displaced femoral neck fractures. In this study, we aimed to ...compare the reoperation rates for different methodologies of internal fixation for femoral neck fractures in young and middle-aged population.
Materials and methods
This a retrospective study. A total of 215 patients with displaced femoral neck fractures treated with cannulated screw fixation were enrolled and divided into the sliding compression and length-stable groups according to the fixation pattern. The occurrence of and reason for revision surgery within one year were recorded. Forty-five patients with complete CT data (including CT scanning on the first postoperative day and at the last follow up) were selected from the total sample. A newly established computerized image processing method was used to evaluate variations in the spatial location of screws.
Results
The reoperation rate was significantly higher in the length-stable group (23.8%) than in the sliding compression group (7.3%). The rate of revision surgery due to nonunion was also higher in the length-stable group (11.4%) than in the sliding compression group (1.8%). However, no significant difference was observed in terms of joint penetration or soft tissue irritation. The sliding compression group (6.58 ± 3.18 mm) showed higher femoral neck shortening than length-stable group (4.16 ± 3.65 mm). When analyzing the spatial variations, a significantly greater screw withdrawal distance was observed in the sliding compression group than in the length-stable group, but with a smaller rotation angle.
Conclusion
Length-stable internal fixation of displaced femoral neck fractures may lead to an increased reoperation rate in young and middle-aged population.
Trial registration
Name of the registry: Chinese Clinical Trial Registry.
Trial registration number: ChiCTR2000032327.
Trial registration date: 2020–4-26.
To compare neoadjuvant chemotherapy (nCT) with CAPOX alone versus neoadjuvant chemoradiotherapy (nCRT) with capecitabine in locally advanced rectal cancer (LARC) with uninvolved mesorectal fascia ...(MRF).
nCRT is associated with higher surgical complications, worse long-term functional outcomes, and questionable survival benefits. Comparatively, nCT alone seems a promising alternative treatment in lower-risk LARC patients with uninvolved MRF.
Patients between June 2014 and October 2020 with LARC within 12 cm from the anal verge and uninvolved MRF were randomly assigned to nCT group with 4 cycles of CAPOX (Oxaliplatin 130 mg/m2 IV day 1 and Capecitabine 1000 mg/m2 twice daily for 14 d. Repeat every 3 wk) or nCRT group with Capecitabine 825 mg/m² twice daily administered orally and concurrently with radiation therapy (50 Gy/25 fractions) for 5 days per week. The primary end point is local-regional recurrence-free survival. Here we reported the results of secondary end points: histopathologic response, surgical events, and toxicity.
Of the 663 initially enrolled patients, 589 received the allocated treatment (nCT, n=300; nCRT, n=289). Pathologic complete response rate was 11.0% (95% CI, 7.8-15.3%) in the nCT arm and 13.8% (95% CI, 10.1-18.5%) in the nCRT arm ( P =0.33). The downstaging (ypStage 0 to 1) rate was 40.8% (95% CI, 35.1-46.7%) in the nCT arm and 45.6% (95% CI, 39.7-51.7%) in the nCRT arm ( P =0.27). nCT was associated with lower perioperative distant metastases rate (0.7% vs. 3.1%, P =0.03) and preventive ileostomy rate (52.2% vs. 63.6%, P =0.008) compared with nCRT. Four patients in the nCT arm received salvage nCRT because of local disease progression after nCT. Two patients in the nCT arm and 5 in the nCRT arm achieved complete clinical response and were treated with a nonsurgical approach. Similar results were observed in subgroup analysis.
nCT achieved similar pCR and downstaging rates with lower incidence of perioperative distant metastasis and preventive ileostomy compared with nCRT. CAPOX could be an effective alternative to neoadjuvant therapy in LARC with uninvolved MRF. Long-term follow-up is needed to confirm these results.
T follicular helper (Tfh) cells play critical roles for germinal center responses and effective humoral immunity. We report here that mTOR in CD4 T cells is essential for Tfh differentiation. In
...mice, both constitutive and inducible Tfh differentiation is severely impaired, leading to defective germinal center B cell formation and antibody production. Moreover, both mTORC1 and mTORC2 contribute to Tfh and GC B cell development but may do so via distinct mechanisms. mTORC1 mainly promotes CD4 T cell proliferation to reach the cell divisions necessary for Tfh differentiation, while Rictor/mTORC2 regulates Tfh differentiation by promoting Akt activation and TCF1 expression without grossly influencing T cell proliferation. Together, our results reveal crucial but distinct roles for mTORC1 and mTORC2 in CD4 T cells during Tfh differentiation and germinal center responses.
Sichuan dark brick tea (
Camellia sinensis
) and Sichuan Fuzhuan brick tea have significantly different aroma characteristics although both of them have almost the same processing methods. Thus, ...these two types of tea were used as the research materials to determine the differences in their aroma compounds. The volatile compounds in the two types of tea were identified and quantified by headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME–GC–MS), results showed that they both had 37 common volatile compounds. Then the aroma-active components were identified by odour activity value (OAV). It was found that SFBT had 20 aroma-active components, of which β-ionone had the largest OAV (199547.72). SDBT has 21 aroma-active ingredients (including all 20 aroma-active components of SFBT), of which β-ionone again has the largest OAV (114800.66). Finally, the aroma profile differences between the two tea samples were studied by aroma profile tests, and the results showed that the main aroma differences of SDBT and SFBT were caused by β-ionone, epoxydihydrolinalool II, methyl salicylate, geranylacetone, nerolidol, benzaldehyde, benzyl acetate, nonanal,
trans
,
trans
-2,4-heptadienal and 1-octen-3-ol, in addition, defined SFBT’s ‘fungi flower aroma’ and SDBT’s ‘aged fragrance’ from the level of aroma monomer.
•Novel sandwich square tube, filling plate-lattice into square tube, was proposed.•The axial and lateral crushing performances of square tubes are enhanced.•Plate-lattice can effectively improve the ...stability of progressive collapse of PLFSST.
In this work, a kind of novel sandwich square tube, filling plate-lattice into square tube, was proposed and preparation by 3D printing. The axial and lateral crushing performances of plate-lattice filled sandwich square tube (PLSST) were investigated by a combined experimental–numerical method. The experimental results were in good agreement with the numerical prediction. The results showed that load bearing and specific energy absorption capability (SEA) of sandwich square tube could be significantly increased by filling plate-lattice under axial and lateral crushing. Reinforcement mechanism is that plate-lattice filler in PLFSST can effectively improve the stability of progressive collapse and alter the compressive deformation mode of PLFSST, resulting in elevating crushing performance and energy absorption capability of PLFSST.
Sauce-aroma Baijiu (SAB) is one of the most famous Baijius in China; SAB has more than 500 aroma compounds in it. However, the key aroma compound in SAB flavor remains unclear. Volatiles play an ...important role in SAB aroma and are highly correlated to SAB quality. In the present study, 63 volatile compounds were quantified among 66 SAB samples using gas chromatography with flame ionization detector (GC-FID). The authors analyzed odor contributions and volatile compound correlations in two quality groups of SAB samples. Moreover, an odor activity value (OAV) ratio-based random forest classifier was used to explain the volatile compound relationship differentiations between the two quality groups. Our results proved higher quality SABs had richer aromas and indicated a set of fruity-like ethyl valerate, green- and malt-like isobutyraldehyde and malt-like 3-methylbutyraldehyde and sweet-like furfural, had closer co-abundance correlations in higher quality SABs. These results indicated that the aroma and contributions of volatile compounds in SABs should be analyzed not only with compound odor activity values, but also the correlations between different aroma compounds.
•The lattice parameter increases, and the average crystallite size decreases with increasing Ce substitution.•Ce substitution can greatly improve the Curie temperature.•Proper amount of Ce ...substitution can improve the magnetic properties of NiZn ferrite.•Ce substitution reduces the dc resistivity and activation energy.
NiZnCe ferrite, Ni0.4Zn0.6−xCexFe2O4 (0 ≤ x ≤ 0.20), were prepared by the sol-gel self-spreading process combing with the solid reaction process. The crystal structure and physical properties of NiZnCe ferrite with different amount of Ce substitution have been studied. The lattice parameter and density rise and the grain size is decreasing with Ce substitution increasing because the ionic radius of Ce3+ ion is much bigger than that of Zn2+ ions, and the atomic weight of Ce3+ ions is heavier than Zn2+ ions. Ms initially increases with increasing amount of Ce substitution because of the increase of density and reduction of porosity, then it decreases when Ce substitution excesses 0.15 which contributes to the increase of the net magnetic moment in tetrahedral site and porosity and the apparence of CeO2 phase. Hc monotonously decreases with Ce substitution increasing due to the mono-domain structure of grains. The initial permeability initially increases at room temperature with the Ce substitution content increasing and has the maximum when the replacement content is 0.15. But it sharply drops when the amount of Ce replacement is 0.20 because the porosity increasing and impurity phase appearance. The Curie temperature has been greatly improved with Ce substitution due to the enhancements of A-B superexchange interactions. The dc resistivity gradually decreases at room temperature due to the fact that Ce substitution reduces the activation energy, and it obeys an exponential decay with the temperature increasing.
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