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Linear codes are widely studied in coding theory as they have nice applications in distributed storage, combinatorics, lattices, cryptography and so on. Constructing linear codes with desirable properties is an interesting research topic. In this paper, based on the augmentation technique, we present two families of linear codes from some functions over finite fields. The first family of linear codes is constructed from monomial functions over finite fields. The weight distribution of the codes is determined in some cases. The codes are proved to be both optimally or almost optimally extendable and self-orthogonal under certain conditions. The localities of the codes and their duals are also studied and we obtain an infinite family of optimal or almost optimal locally recoverable codes. The second family of linear codes is constructed from weakly regular bent functions over finite fields and its weight distribution is explicitly determined. This family of codes is also proved to be both optimally or almost optimally extendable and self-orthogonal. Besides, this family of codes has been proven to have locality 2 or 3 under certain conditions. Particularly, we derive two infinite families of optimal locally recoverable codes. Some infinite families of 2-designs are obtained from the codes in this paper as byproducts.

Cyclic codes are important in theory, as they are closely related to a number of areas of mathematics. Cyclic codes are also important in practice, as they have efficient encoding and decoding algorithms. An infinite family of cyclic codes over ${\mathrm {GF}}(q)$ is said to have linearly-best-known parameters if for any $[n, k, d]$ code ${\mathcal {C}}$ in this family, there is no known $[n, k, d']$ linear code over ${\mathrm {GF}}(q)$ such that $d' > d$ . An infinite family of cyclic codes over ${\mathrm {GF}}(q)$ is said to have cyclicly-best-known parameters if for any $[n, k, d]$ code ${\mathcal {C}}$ in this family, there is no known $[n, k, d']$ cyclic code over ${\mathrm {GF}}(q)$ such that $d' > d$ . It is very rare to see an infinite family of binary cyclic codes with cyclicly-best-known parameters whose duals codes have also cyclicly-best-known parameters. The objective of this paper is to study such family of binary cyclic codes of length $2^{m}-1$ and dimension $2^{m}-1-m(m-1)/2$ , denoted by ${\mathcal {C}}_{(2,m,2)}$ , and their dual codes ${\mathcal {C}}_{(2,m,2)}^{\perp} $ . The weight distribution of ${\mathcal {C}}_{(2,m,2)}^{\perp} $ is settled and the parameters of ${\mathcal {C}}_{(2,m,2)}$ are investigated in this paper. A larger family of binary cyclic codes ${\mathcal {C}}_{(2,m,r)}$ and their duals are also constructed and studied in this paper, where $0 \leq r \leq m-1$ .

BCH codes and their dual codes are two special subclasses of cyclic codes and are the best linear codes in many cases. A lot of progress on the study of BCH cyclic codes has been made, but little is known about the minimum distances of duals of BCH codes. Recently, a concept called dually-BCH code was introduced to investigate the duals of BCH codes and the lower bounds on their minimum distances in Gong et al., (2022). For a prime power $q$ and an integer $m \ge 4$ , let $n=\frac {q^{m}-1}{q+1}$ ( $m$ even), or $n=\frac {q^{m}-1}{q-1}$ ( $q>2$ ). In this paper, some sufficient and necessary conditions in terms of the designed distance will be given to ensure that the narrow-sense BCH codes of length $n$ are dually-BCH codes, which extended the results in Gong et al., (2022). Lower bounds on the minimum distances of their dual codes are developed for $n=\frac {q^{m}-1}{q+1}$ ( $m$ even). As byproducts, we present the largest coset leader $\delta _{1}$ modulo $n$ being of two types, which proves a conjecture in Wu et al., (2019) and partially solves an open problem in Li et al., (2017). We also investigate the parameters of narrow-sense BCH codes of length $n$ with design distance $\delta _{1}$ . The BCH codes presented in this paper have good parameters in general.

Recently, simplicial complexes are used in constructions of several infinite families of minimal and optimal linear codes by Hyun et al. Building upon their research, in this paper more linear codes over the ring $\mathbb {Z}_{4}$ are constructed by simplicial complexes. Specifically, the Lee weight distributions of the resulting quaternary codes are determined and two infinite families of four-Lee-weight quaternary codes are obtained. Compared to the databases of $\mathbb Z_{4}$ codes by Aydin et al., at least nine new quaternary codes are found. Thanks to the special structure of the defining sets, we have the ability to determine whether the Gray images of certain obtained quaternary codes are linear or not. This allows us to obtain two infinite families of binary nonlinear codes and one infinite family of binary minimal linear codes. Furthermore, utilizing these minimal binary codes, some secret sharing schemes as a byproduct also are established.

Agriculture has high requirements for both the quality and quantity of water resources. However, the traditional monitoring methods used in the field of water quality monitoring for agricultural irrigation suffer from issues such as complex operation, low automation, and low efficiency. To address these problems, this study proposes an agricultural irrigation water quality monitoring system based on an inductively coupled plasma optical emission spectrometer and designs the usage process and strategies of the spectrometer according to the characteristics of agricultural irrigation water. The water quality monitoring system can precisely monitor heavy metal elements that may contaminate agricultural irrigation water and eliminate the interference of other impurities. Experimental results show that the system achieves a correlation above 0.999 for the standard curves of five major heavy metal elements, and the signal-to-noise ratio of heavy metal elements reaches 12.56 when the system carrier gas flow rate is 0.8 L/min. Compared to traditional detection methods, the system exhibits higher detection speed, automation, and comparable accuracy, thus demonstrating potential for practical application in the field of water quality monitoring for agricultural irrigation.

Background: Cervical lymph node metastasis from unknown primary sites is a challenging clinical issue with a changing therapy model and unpredictable outcomes, which leads to the difficulty in selecting optimal treatments. Thus, it is valuable to analyze the clinical characteristics and outcomes of the patients who receive different management styles. Methods: All patients with cervical lymph node metastasis from unknown primary sites were reviewed and no primary lesions were found. In addition, this work was funded by the Clinical Trial Fund Project of Tianjin Medical University Cancer Institute and Hospital (No. C1716). Specifically, we used univariate, multiple regression analysis to evaluate the factors associated with prognosis. Results: 365 patients met the inclusion criteria, and the 2- and 5-year survival rates were 77.0% and 33.4%, respectively, with a median survival of 45 months. Gender, age, pathological type, nodal status, and necessary cervical lymph node dissection affected locoregional control. Distant metastasis was common in individuals with a pathological type of adenocarcinoma, poor differentiation, and advanced nodal status. Furthermore, patients who received induction chemotherapy had a better prognosis than those treated with postoperative chemotherapy. Multiple regression analysis showed that pathological grade, treatment models, and distant metastasis were associated with overall survival (OS) and progression-free survival (PFS). In addition, local recurrence exerted a significant influence on OS. Induction chemotherapy and postsurgical radiotherapy seemed to improve the prognosis of patients at the advanced stage compared with simple surgery and postsurgical chemotherapy. Conclusions: Pathological grade, treatment models, and distant metastasis were independent risk factors for prognosis. Induction chemotherapy or postoperative radiotherapy benefited patients at the advanced stage, and patients with adenocarcinoma, poor differentiation, and advanced nodal status should undergo induction chemotherapy in light of the increased risk of distant metastasis.

In this paper, we propose a novel study for gesture identification using surface electromyography (sEMG) signal, and the raw sEMG signal and the sEMG envelope signal are collected by the sensor at the same time. An efficient method of gesture identification based on the combination of two signals using supervised learning and univariate feature selection is implemented. In previous research techniques, researchers tend to use the raw sEMG signal and extract several constant features for classification, which inevitably causes a result of ignoring individual differences. Our experiment shows that both the optimal feature set and redundant feature set are not same for different subjects. In order to address this problem, we extract all the common features from two signals, up to 76 features, most of which has been established as the common EMG-based gesture index. In addition, extracting too many features in an application can reduce operational efficiency, so we apply for feature selection to get the optimal feature set and decrease the number of extracting feature. As a result, the combination of two signals is better than using a single signal. The feature selection can be used to select optimal feature set from all features to achieve the best classification performance for each subject. The experimental results demonstrate that the proposed method achieves the performance with the highest accuracy of 95% for identifying up to nine gestures only using two sensors. Finally, we develop a real-time intelligent sEMG-driven bionic hand system by using the proposed method.

Extracellular ATP (eATP) plays an essential role in plant growth, development, and stress tolerance. Here, we report that eATP participated in Nicotiana tabacumpollen germination (PG) and pollen tube growth (PTG) by regulating K+and Ca2+influx. Exogenous ATP or ADP effectively promoted PG and PTG in a dose-dependent manner; weakly hydrolysable ATP analog (ATPγS) showed a similar effect. AMP, adenosine, adenine, and phosphate did not affect PG or PTG. Within a certain range, higher concentrations of K+or Ca2+in the medium increased the effect of ATP in promoting PG and PTG. However, in mediums containing K+or Ca2+concentrations above this range, the effect of ATP was reversed, resulting in PG and PTG inhibition. Ca2+chelators (EGTA), Ca2+channel blockers, and K+channel blockers suppressed ATP-promoted PG and PTG. Results from a patch clamp showed that ATP activated a K+and Ca2+influx in pollen protoplasts. These results suggest that, as an apoplastic signal, eATP may be involved in PG and PTG via regulating Ca2+and K+absorption.

Thyroglobulin (Tg) measurement in fine-needle aspiration (FNA-Tg) has proved to be an excellent tool to identify metastatic cervical lymph nodes (CLN) before or after surgery for papillary thyroid cancer (PTC). The diagnostic value of FNA-Tg for metastatic CLN in PTC patients is higher than that of ultrasound (US) and fine-needle aspiration cytology (FNAC), especially for small or cystic LN. The combination of FNAC and FNA-Tg can provide nearly 100% diagnostic sensitivity and specificity for CLN metastasis. However, the cutoff values of FNA-Tg for metastatic CLN have not been standardized, and the reported cutoff values of FNA-Tg range from 0.2 ng/ml to 77 ng/ml because of the differences in study samples, Tg measurement methods, Tg assays kits, etc. Serum anti-thyroglobulin antibody level, serum thyroglobulin level, the presence or absence of thyroid glands, and the characteristics of CLN may be factors affecting the accuracy of FNA-Tg. This review summarizes the recent research on the application of FNA-Tg in the diagnosis of metastatic LN in PTC and provides a reliable basis for the clinical diagnosis of cervical lymph node metastasis.

Issues about commercialization of space have been a growing concern in the past decade for the space community. This paper focuses on the work from a team of 51 students attending the Summer Session Program of the International Space University in Bremen, Germany. CASH 2021 (Commercial Access and Space Habitation) documents a plan that identifies commercial opportunities for space utilization that will extend human presence in space, and will chart the way forward for the next 20 years. The group selected four commercial sectors that show the most promise for the future: tourism, entertainment, space system service, assembly and debris removal, and research and development/production. The content of this document presents the results of their research. Historical activities in each of the commercial sectors are reviewed along with the current market situation. To provide a coherent background for future commercialization possibilities a scenario has been developed. This scenario includes a postulated upon ideal future and includes social, political and economic factors that may affect the space industry over the timeline of the study. The study also presents a roadmap, within the limited optimistic scenario developed, for the successful commercialization of space leading to future human presence in space. A broad range of commercially viable opportunities, not only within the current limits of the International Space Station, but also among the many new developments that are expected by 2021 are discussed.

With the improvement of the accuracy of the inertial system, the influence of the disturbing gravity field on the accuracy of long-range rocket has become increasingly prominent. However, in actual engineering, there are problems of low accuracy and being time-consuming for disturbing gravity field compensation. In view of this, this paper proposes a set of online comprehensive solutions combining disturbing gravity reconstruction and stellar correction. According to the pre-launch binding parameters, the net function assignment method is used in the navigation system to calculate disturbing gravity in the boost phase online. In the guidance system, a closed-loop guidance online compensation method is proposed based on the state-space perturbation method for the disturbing gravity in the coast phase. At the same time, the vertical deflection can also be corrected by stellar guidance. The calculation results are simulated and verified under different circumstances. Simulation results show that the proposed online compensation algorithm has an accuracy improvement compared with the element compensation algorithm on ground. And the stellar guidance algorithm can further correct the impact deviation. The impact deviation after comprehensive compensation does not exceed 50 m, and the compensation percentage is greater than 65%.

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Rapid and reversible G-quadruplex hairpin dimer formation is observed for bisoligonucleotide conjugates possessing stilbenediether Sd linkers connecting two short polyG sequences.

Rapid and reversible G-quadruplex hairpin dimer formation is observed for bis(oligonucleotide) conjugates possessing stilbenediether (Sd) linkers connecting two short poly(G) sequences.