17 research outputs found
Anomalous photoluminescence in InP1-xBix
Low temperature photoluminescence (PL) from InP1-xBix thin films with Bi concentrations in the 0-2.49% range reveals anomalous spectral features with strong and very broad (linewidth of 700 nm) PL signals compared to other bismide alloys. Multiple transitions are observed and their energy levels are found much smaller than the band-gap measured from absorption measurements. These transitions are related to deep levels confirmed by deep level transient spectroscopy, which effectively trap free holes and enhance radiative recombination. The broad luminescence feature is beneficial for making super-luminescence diodes, which can theoretically enhance spatial resolution beyond 1 ?m in optical coherent tomography (OCT)
Apple grading method based on neural network with ordered partitions and evidential ensemble learning
In order to improve the performance of the automatic apple grading and sorting system, in this paper, an ensemble model of ordinal classification based on neural network with ordered partitions and Dempster–Shafer theory is proposed. As a non-destructive grading method, apples are graded into three grades based on the Soluble Solids Content value, with features extracted from the preprocessed near-infrared spectrum of apple serving as model inputs. Considering the uncertainty in grading labels, mass generation approach and evidential encoding scheme for ordinal label are proposed, with uncertainty handled within the framework of Dempster–Shafer theory. Constructing neural network with ordered partitions as the base learner, the learning procedure of the Bagging-based ensemble model is detailed. Experiments on Yantai Red Fuji apples demonstrate the satisfactory grading performances of proposed evidential ensemble model for ordinal classification. © 2022 The Authors. CAAI Transactions on Intelligence Technology published by John Wiley & Sons Ltd on behalf of The Institution of Engineering and Technology and Chongqing University of Technology.open access</p
Integrin β1 in Pancreatic Cancer: Expressions, Functions, and Clinical Implications
Pancreatic cancer (PC) is characterized by rapid progression and a high mortality rate. The current treatment is still based on surgical treatment, supplemented by radiotherapy and chemotherapy, and new methods of combining immune and molecular biological treatments are being explored. Despite this, the survival rate of PC patients is still very disappointing. Therefore, clarifying the molecular mechanism of PC pathogenesis and developing precisely targeted drugs are key to improving PC prognosis. As the most common β subunit of the integrin family, integrin β1 has been proved to be closely related to the vascular invasion, distant metastasis, and survival of PC patients, and treatment targeting integrin β1 in PC has gained initial success in animal models. In this review, we summarize the various signaling pathways by which integrins are involved in PC, focusing on the roles of integrin β1 in the malignant behaviors of PC. Additionally, recent studies regarding the feasibility of integrin β1 as a diagnostic and prognostic biomarker in PC are also discussed. Finally, we present the progress of several integrin β1-based clinical trials to highlight the potential of integrin β1 as a target for personalized therapy in PC
Antisense Oligodeoxynucleotide Inhibition as an Alternative and Convenient Method for Gene Function Analysis in Pollen Tubes
<div><p>Antisense oligodeoxynucleotide (A-ODN) inhibition works well in animal cells. However, there have been few successful examples to date of its application in plants, and more specifically whether the technique can be used in pollen tubes as a model of plant cell growth. NtGNL1 plays an important role in pollen tube development and was thus selected as an indicator to assess the biological effects of A-ODN. An A-ODN inhibition technique was used to down-regulate NtGNL1 expression in tobacco pollen tubes and showed that A-ODNs could quickly enter pollen tubes through the thick wall and cell membrane and effectively block NtGNL1 expression. Phenotype analysis revealed that the down-regulation of NtGNL1 by A-ODNs resulted in abnormalities in endocytosis and subsequent vesicle trafficking, similar to the phenotypes of pollen tubes treated with NtGNL1 RNAi. This investigation confirmed that A-ODNs could specifically inhibit target gene expression, and furthermore demonstrated that A-ODN functioned in a concentration- and duration-dependent manner, because A-ODNs could be degraded when incubated with pollen tubes. Thus, the A-ODN technique was successfully used for gene function analysis in pollen tubes and appears to be an alternative and convenient technique when the <i>in vitro</i> pollen tube is used as the study model. This technique will greatly facilitate investigations on the molecular mechanism(s) underlying pollen tube growth.</p> </div
Fluorescent distribution pattern showing uptake FM4-64 within 30 minutes into control and A-ODN treated pollen tubes.
<p>A: fluorescent images of a control pollen tube, C: an A-ODN-treated pollen tube. B and D: pixel values (calculated by ImageJ 1.37 v) along a central transect through A and C. Different pixel values curves means different fluorescent distribution pattern. Bar = 20 µm.</p
Tracing the uptake of antisense ODN into pollen tubes.
<p>A<b>:</b> Tracing the uptake of FL-ODNs. FL-ODNs signal appeared as small dots in pollen tubes after 1 hour’s incubation (a). After 2 hours’ incubation, the signal concentrated at the tip of the pollen tube (b) and finally dispersed evenly throughout the entire pollen tube after 3 hour’s incubation (c). a–c Bar = 20 µm. B<b>:</b> Pulse-chasing labeling with fluorescence-labeled ODNs and FM4-64. (a) Bright field image of the pollen tube. (b) The image show the same pollen tube labeled with Alexa Fluor 488 fluorescence. (c) The image show the same pollen tube labeled with FM4-64 fluorescence. (d) Pulse-chase labeling with Alexa Fluor 488 for 3 h followed by FM4-64 for 10 min. Squares (e–g) indicate areas magnified in (d), respectively. Bar = 20 µm in (a–d); bar = 10 µm in (e–g). n = 15–20 for the observation of each stages during FL-ODNs uptake.</p
Photoluminescence of InGaAs/GaAsBi/InGaAs type-II quantum wells grown by gas source molecular beam epitaxy
InxGa1-xAs/GaAs1-yBiy/InxGa1-xAs (0.20 ≤x ≤0.22, 0.035 ≤y ≤0.045) quantum wells (QWs) were grown on GaAs substrates by gas source molecular beam epitaxy for realizing the type-II band edge line-up. Both type-I and type-II transitions were observed in the Bi containing W QWs and the photoluminescence intensity was enhanced in the sample with a high Bi content, which is mainly due to the improvement of carrier confinement. The 8 band k • p model was used to analyze the electronic properties in the QWs and the calculated transition energies fit well with the experiment results. Our study shows that the proposed type-II QW is a promising candidate for realizing GaAs-based near infrared light emitting devices near 1.3 μ
Sequences and selected positions of antisense ODN.
<p>Sequences and selected positions of antisense ODN.</p
Inhibition effects of A-ODN on pollen germination and pollen tube growth.
<p>A, Up to 80% of the control, wild-type pollen germinated after 4 h of culturing, whereas less than 60% of the pollen in antisense ODN media germinated (<i>n</i> = 300). Double asterisks indicate P<0.01 between control (ck) and treated sample [SPSS (16.0) Independent-Sample T Test]. Error bars in the columns represent SD. B, A bright field image showing pollen grains germinated in control (CK) after 4 h. C, Approximately half of the pollen grains germinated in A-ODN (20 µM) medium at the same time. Bar = 50 µm. D, E, Pollen tube length comparison between control and A-ODN (5 µM) treated pollen tubes. Pollen tubes in control media (D) were clearly longer than those grown in A-ODN medium (E). Bar = 100 µm. E–I, Phenotypes of A-ODN (20 µM) treated pollen tubes: bulging (F), curved (G), zigzag (H), bending (I).</p
The effect of A-ODNs on pollen tube growth and <i>NtGNL1</i> expression level.
<p>A: Inhibition effects among antisense ODNs (1.0 µM). n = 300±10. Pollen tubes under ON4 and ON6 treatment were obvious shorter than that under other treatment. Asterisks indicate a significant difference (<i>P</i><0.05). These data were calculated and analyzed by SPSS (16.0) Independent-Sample T Test. Error bars in the columns represent SD. B: No significant inhibition effect on pollen tubes growth was observed during treatment by sense and random ODNs. n = 300±10. C: the effect of antisense ODN treatment on <i>NtGNL1</i> mRNA expression. D: the comparison of cytotoxic effect between control (sense or nonsense) and antisense ON4. All of them displayed around 80% viability. n = 300±10.</p