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Nowadays, lots of applications and websites utilize text-based captchas to partially protect the authentication mechanism. However, in recent years, different ways have been exploited to automatically recognize text-based captchas especially deep learning-based ways, such as, convolutional neural network (CNN). Thus, we have to enhance the text captchas design. In this paper, using the features of the randomness for each encoding process in visual cryptography (VC) and the visual recognizability with naked human eyes, VC is applied to design and enhance text-based captcha. Experimental results using two typical deep learning-based attack models indicate the effectiveness of the designed method. By using our designed VC-enhanced text-based captcha (VCETC), the recognition rate is in some degree decreased.

Brackish water has been utilized extensively in agriculture around the world to cope with the global water deficit, but soil salt accumulation caused by brackish water irrigation cannot be ignored. Straw incorporation has been confirmed an effective sustainable means to inhibit soil salt accumulation. An experiment was conducted in growth tanks over two consecutive growing seasons to investigate the effects of wheat straw incorporation on soil moisture and salinity under brackish water irrigation (5g NaCl L−1). Furthermore, the trial investigated the effects of three wheat straw cutting lengths (CK = 0 cm; L1 = 5 cm, L2 = 10 cm, and L3 = 20 cm) on soil water-salt dynamics and summer maize growth. The results showed that soil properties and maize yields were favorably and significantly affected by the shorter straw segments incorporated into the cultivated field (p < 0.05), as indicated in the decrease in soil bulk density (7.47%−7.79%) and the rise of soil organic matter (SOM) content (2.4−4.5g kg−1) and soil total porosity (4.34%−4.72%) under treatment L1. Meanwhile, treatment L1 produced the greatest dry above-ground biomass (14447 ± 571 kg ha−1), 100-grain weight (34.52 ± 1.20 g) and grain yield (7251 ± 204 kg ha−1) of summer maize. Soil water content in the cultivated layer increased 4.79%−25.44%, and the soil salt accumulation rate decreased significantly due to the straw incorporation and the highest value of soil moisture content (19.10%−21.84%), as well as the lowest value of soil salt accumulation rates (2.12−9.06) obtained at treatment L1. Straw incorporation with cutting length in 5 cm is the optimal choice for alleviating the adverse effects due to brackish water irrigation and improving soil properties, which could be helpful for agricultural mechanization and straw field-returning practices.

The accelerated decline in Arctic sea ice in recent decades suggests the possibility of future trans-Arctic shipping routes linking the Atlantic and Pacific oceans, with significant implications for the global economy. We present a projection of Arctic sea ice conditions and shipping activities during the 21st century based on 16 CMIP6 models calibrated to remove spatial biases. The multimodel ensemble mean shows that the Arctic is likely to be ice-free in September by 2076 and 2055 under the SSP2-4.5 and SSP5-8.5 scenarios, respectively, whereas the extent of sea ice is >2 × 10 ^6 km ^2 throughout the 21st century under the SSP1-2.6 scenario. The Arctic sea ice in September thins over time, leading to a reduction in the area with an ice thickness >120 cm (i.e. the threshold over which sea ice is inaccessible to Type A vessels) by 34–100% by the late 21st century (2086–2100) under the three scenarios. Given the declines in the extent and thickness of sea ice, the most commonly traversed route along the North West Passage tends to migrate from the southern to the northern route during the 21st century. The optimum route along the Northern Sea Route shifts northward with time, with the Transpolar Sea Route becoming available. Quantitatively, the maritime accessibility to Type A vessels via the Transpolar Sea Route increases from ∼6.7, 4.2 and 2.1% in 2021–2035 to 14.7, 29.2 and 67.5% in 2086–2100 under the SSP1-2.6, SSP2-4.5 and SSP5-8.5 scenarios, respectively. The season for trans-Arctic shipping extends from 5 to ∼7.5 (9) months by the late 21st century under the SSP1-2.6 (SSP2-4.5) scenario and the Arctic becomes navigable all year round under the SSP5-8.5 scenario. These findings may aid in developing strategic planning by governments for the Arctic and providing strategic advice for the global maritime industry.

Carbon emission trading is an important countermeasure for countries around the world to cope with the challenge of climate change. Price signals in the carbon market play an important stabilizing role. Therefore, research on the factors affecting carbon price fluctuations is of great significance. Based on this, an empirical study on the fluctuation factors of carbon price in China’s pilot carbon market showed that: gross industrial output, coal consumption and the number of extreme weather have a positive impact on carbon prices, while the technology innovation index has a negative impact on carbon prices. This article puts forward suggestions on the construction of the carbon market, stabilizes carbon prices, and promotes the development of China’s carbon market.

Palladium-doped nanoscale zerovalent iron nanoparticles (Fe-Pd NPs) was fabricated and stabilized by poly (γ-glutamic acid)–Dopamine composite (PGA-DA). The fabricated nanoparticles had high dechlorination activity towards p-Chlorophenol (p-CP). PGA-DA modified Fe-Pd NPs significantly outperformed PGA modified ones in catalytic activities even in weak alkaline condition. Fe-Pd NPs@PGA-DA (10 mg PGA-DA and 0.4 wt% Pd loading) could achieve 100 % p-CP removal within 60 min. It is worth mentioning that the presence of DA alone could overwhelm dechlorination capacity of Fe-Pd NPs toward p-CP. The coordination bonding between catechol and Fe ions was also investigated in detail. This study demonstrated that PGA-DA is a promising modifier and stabilizer for Fe-Pd NPs, which was expected to be applied in real environmental remediation technology.

The selective recognition of metal ions is very important and the development of novel chemosensor is still a challenge. Herein, a single dual-emissive fluorescence probe was developed to detect Fe3+ and phytic acid (PA). Red quantum dots (CdSe) were embedded into silica nanoparticles for an internal standard emission, whereas blue carbon dots (CDs) were covalently linked onto the surface of silica as a sensing element to achieve a more precise and sensitive detection. The fluorescence of the CDs was effectively quenched by Fe3+ via a photoinduced electron transfer (PET) process. Fe3+ could selectively bind to phytic acid, thus leading to the recovered fluorescence of the CDs in the presence of Fe3+. Upon addition of PA to the CdSe@SiO2-CDs/Fe(III) complex dispersion, the fluorescence of the CDs significantly increased. The ratiometric probe enabled the selective detection of PA within 0.08-1.6 mM and a limit of detection of 1.5 μM. Overall, this method provided high selectivity, stability, and recovery ratio in the detection of Fe3+ and PA.

Ochratoxin A (OTA) is a type of mycotoxin generated from the metabolism of Aspergillus and Penicillium, and is extremely toxic to humans, livestock, and poultry. However, traditional assays for the detection of OTA are expensive and complicated. Other than OTA aptamer, OTA itself at high concentration can also adsorb on the surface of gold nanoparticles (AuNPs), and further inhibit AuNPs salt aggregation. We herein report a new OTA assay by applying the localized surface plasmon resonance effect of AuNPs and their aggregates. The result obtained from only one single linear calibration curve is not reliable, and so we developed a “double calibration curve” method to address this issue and widen the OTA detection range. A number of other analytes were also examined, and the structural properties of analytes that bind with the AuNPs were further discussed. We found that various considerations must be taken into account in the detection of these analytes when applying AuNP aggregation-based methods due to their different binding strengths.

Background: Understanding the development of post-traumatic stress disorder (PTSD) is a precondition for efficient risk assessment and prevention planning. Studies to date have been site and sample specific. Towards developing generalizable models of PTSD development and prediction, the International Consortium to Predict PTSD (ICPP) compiled data from 13 longitudinal, acute-care based PTSD studies performed in six different countries. Objective: The objectives of this study were to describe the ICPP’s approach to data pooling and harmonization, and present cross-study descriptive results informing the longitudinal course of PTSD after acute trauma. Methods: Item-level data from 13 longitudinal studies of adult civilian trauma survivors were collected. Constructs (e.g. PTSD, depression), measures (questions or scales), and time variables (days from trauma) were identified and harmonized, and those with inconsistent coding (e.g. education, lifetime trauma exposure) were recoded. Administered in 11 studies, the Clinician Administered PTSD Scale (CAPS) emerged as the main measure of PTSD diagnosis and severity. Results: The pooled data set included 6254 subjects (39.9% female). Studies’ average retention rate was 87.0% (range 49.1–93.5%). Participants’ baseline assessments took place within 2 months of trauma exposure. Follow-up durations ranged from 188 to 1110 days. Reflecting studies’ inclusion criteria, the prevalence of baseline PTSD differed significantly between studies (range 3.1–61.6%), and similar differences were observed in subsequent assessments (4.3–38.2% and 3.8–27.0% for second and third assessments, respectively). Conclusion: Pooling data from independently collected studies requires careful curation of individual data sets for extracting and optimizing informative commonalities. However, it is an important step towards developing robust and generalizable prediction models for PTSD and can exceed findings of single studies. The large differences in prevalence of PTSD longitudinally cautions against using any individual study to infer trauma outcome. The multiplicity of instruments used in individual studies emphasizes the need for common data elements in future studies.

Using response surface method to determine the optimal technological conditions of biomass-based precursor preparation, magnetic Fe3O4 particles were loaded on the surface and internal channel of biomass-based precursor to prepare a magnetic biomass-based solid acid catalyst using the sol-gel method. To investigate the performance of the magnetic catalyst, it was used to hydrolyze cellulose into reducing sugar, whose structure was characterized by infrared spectrum analysis. The optimum process conditions of biomass-based precursor preparation was obtained by quadratic regression model as a carbonization temperature of 549 °C, carbonization time of 13 h, sulfonating temperature of 121 °C, and sulfonating time of 6 h. Using the biomass-based solid acid catalyst to hydrolyze cellulose, a reducing sugar yield of 57.36% was obtained. Compared with the traditional solid acid catalysts, the total reducing sugar yield was increased by 65%. The infrared spectrum analysis showed that magnetic Fe3O4 particles were combined successfully with biomass-based precursor. This magnetic biomass-based solid acid catalyst has a carbon structure layer of vermicular disorder and possesses high stability.

In this study, we developed a reflective localized surface plasmon resonance (LSPR) optical fiber sensor, based on silver nanoparticles (Ag NPs). To enhance the sensitivity of the LSPR optical sensor, two key parameters were optimized, the length of the sensing area and the coating time of the Ag NPs. A sensing length of 1.5 cm and a 1-h coating time proved to be suitable conditions to produce highly sensitive sensors for biosensing. The optimized sensor has a high refractive index sensitivity of 387 nm/RIU, which is much higher than that of other reported individual silver nanoparticles in solutions. Moreover, the sensor was further modified with antigen to act as a biosensor. Distinctive wavelength shifts were found after each surface modification step. In addition, the reflective LSPR optical fiber sensor has high reproducibility and stability.

Background: Patellofemoral osteoarthritis commonly occurs in older people, often resulting in anterior knee pain and severely reduced quality of life. The aim was to examine the effectiveness of arthroscopic patelloplasty and circumpatellar denervation for the treatment of patellofemoral osteoarthritis (PFOA). Methods: A total of 156 PFOA patients (62 males, 94 females; ages 45-81 years, mean 66 years) treated in our department between September 2012 and March 2013 were involved in this study. Clinical manifestations included recurrent swelling and pain in the knee joint and aggravated pain upon ascending/descending stairs, squatting down, or standing up. PFOA was treated with arthroscopic patelloplasty and circumpatellar denervation. The therapeutic effects before and after surgery were statistically evaluated using Lysholm and Kujala scores. The therapeutic effects were graded by classification of the degree of cartilage defect. Results: A total of 149 cases were successfully followed up for 14.8 months, on average. The incisions healed well, and no complications occurred. After surgery, the average Lysholm score improved from 73.29 to 80.93, and the average Kujala score improved from 68.34 to 76.48. This procedure was highly effective for patients with cartilage defects I-III but not for patients with cartilage defect IV. Conclusions: For PFOA patients, this procedure is effective for significantly relieving anterior knee pain, improving knee joint function and quality of life, and deferring arthritic progression.

Determination of the physicochemical properties of protein therapeutics and their aggregates is critical for developing formulations that enhance product efficacy, stability, safety and manufacturability. Analytical challenges are compounded for materials: (1) that are formulated at high concentration, (2) that are formulated with a variety of excipients, and (3) that are available only in small volumes. In this article, a new instrument is described that measures protein secondary and tertiary structure, as well as molecular size, over a range of concentrations and formulation conditions of low volume samples. Specifically, characterization of colloidal and conformational stability is obtained through a combination of two well-established analytical techniques: dynamic light scattering (DLS) and Raman spectroscopy, respectively. As the data for these two analytical modalities are collected on the same sample at the same time, the technique enables direct correlation between them, in addition to the more straightforward benefit of minimizing sample usage by providing multiple analytical measurements on the same aliquot non-destructively. The ability to differentiate between unfolding and aggregation that the combination of these techniques provides enables insights into underlying protein aggregation mechanisms. The article will report on mechanistic insights for aggregation that have been obtained from the application of this technique to the characterization of lysozyme, which was evaluated as a function of concentration and pH.