An Investigation of the Effect of Chitosan on Isothermal Crystallization, Thermal Decomposition, and Melt Index of Biodegradable Poly(L-lactic acid)

Biodegradable chitosan (CS) was introduced into another biodegradable poly(L-lactic acid) (PLLA) to prepare the PLLA/CS composites, and the effect of CS on thermal behavior and melt index of PLLA was investigated using modern testing technologies including optical depolarizer, thermogravimetric analysis instrument, and melt index instrument. The relevant testing results showed that both crystallization temperature and CS concentration affected the isothermal crystallization behavior of PLLA. Compared to neat PLLA, the t1/2 of PLLA/5% CS decreased from 2991.54 s to the minimum value 208.76 s at 105°C. However, the t1/2 of PLLA/CS composites in high crystallization temperature zone was different from that in low crystallization temperature zone. The increase of CS concentration and heating rate made the thermal decomposition temperature of PLLA/CS composites shift to higher temperature. The melt index results indicated that 3% CS made the fluidity of PLLA become better

cis-Bis(1,10-phenanthroline-κ2 N,N′)bis­(thio­cyanato-κN)magnesium(II)

The title compound, [Mg(NCS)2(C12H8N2)2], has been synthesized from the hydro­thermal reaction of MgCl2, KSCN, 1,10-phenanthroline and H2O. Its structure is isotypic with the MnII, FeII, CoII, NiII, CuII and ZnII analogues. The MgII cation has a slightly distorted octa­hedral geometry containing four N atoms from two 1,10-phenanthroline mol­ecules and two N atoms from two thio­cyanate anions. The asymmetric unit contains one-half mol­ecule, and the complete complex has 2 symmetry

A Hybrid Secure Scheme for Wireless Sensor Networks against Timing Attacks Using Continuous-Time Markov Chain and Queueing Model

Wireless sensor networks (WSNs) have recently gained popularity for a wide spectrum of applications. Monitoring tasks can be performed in various environments. This may be beneficial in many scenarios, but it certainly exhibits new challenges in terms of security due to increased data transmission over the wireless channel with potentially unknown threats. Among possible security issues are timing attacks, which are not prevented by traditional cryptographic security. Moreover, the limited energy and memory resources prohibit the use of complex security mechanisms in such systems. Therefore, balancing between security and the associated energy consumption becomes a crucial challenge. This paper proposes a secure scheme for WSNs while maintaining the requirement of the security-performance tradeoff. In order to proceed to a quantitative treatment of this problem, a hybrid continuous-time Markov chain (CTMC) and queueing model are put forward, and the tradeoff analysis of the security and performance attributes is carried out. By extending and transforming this model, the mean time to security attributes failure is evaluated. Through tradeoff analysis, we show that our scheme can enhance the security of WSNs, and the optimal rekeying rate of the performance and security tradeoff can be obtained. View Full-Tex

The juxtamembrane and carboxy-terminal domains of Arabidopsis PRK2 are critical for ROP-induced growth in pollen tubes.

Polarized growth of pollen tubes is a critical step for successful reproduction in angiosperms and is controlled by ROP GTPases. Spatiotemporal activation of ROP (Rho GTPases of plants) necessitates a complex and sophisticated regulatory system, in which guanine nucleotide exchange factors (RopGEFs) are key components. It was previously shown that a leucine-rich repeat receptor-like kinase, Arabidopsis pollen receptor kinase 2 (AtPRK2), interacted with RopGEF12 for its membrane recruitment. However, the mechanisms underlying AtPRK2-mediated ROP activation in vivo are yet to be defined. It is reported here that over-expression of AtPRK2 induced tube bulging that was accompanied by the ectopic localization of ROP-GTP and the ectopic distribution of actin microfilaments. Tube depolarization was also induced by a potentially kinase-dead mutant, AtPRK2K366R, suggesting that the over-expression effect of AtPRK2 did not require its kinase activity. By contrast, deletions of non-catalytic domains in AtPRK2, i.e. the juxtamembrane (JM) and carboxy-terminal (CT) domains, abolished its ability to affect tube polarization. Notably, AtPRK2K366R retained the ability to interact with RopGEF12, whereas AtPRK2 truncations of these non-catalytic domains did not. Lastly, it has been shown that the JM and CT domains of AtPRK2 were not only critical for its interaction with RopGEF12 but also critical for its distribution at the plasma membrane. These results thus provide further insight into pollen receptor kinase-mediated ROP activation during pollen tube growth

The application of daily interruption in the treatment of analgesia and sedation in general ICU

目的  探讨在综合ICU镇痛镇静患者护理方面实施每日唤醒疗法护理的方法和效果。方法  选择在ICU进行持续镇痛镇静治疗>24h的患者共90例，实施每日唤醒和相应护理计划并观察记录。结果  实施每日唤醒后，镇痛镇静药物用量减少，机械通气时间减少，与镇静相关的躁动、谵妄事件减少，住ICU时间缩短。结论  ICU镇痛镇静患者实施每日唤醒可有利于其疾病恢复，减少镇静相关不良事件，值得临床关注，但必须加强病情监测和安全护理。Objective: To explore method and effect of daily interruption therapy in the treatment of analgesia and sedation in general ICU. Methods: 90 patients in ICU, who had been treated with continuous analgesia therapy within 24 hours, were selected and would receive daily interruption therapy and corresponding nursing. Results: Analgesic dosage of sedative drugs was reduced, together with mechanical ventilation time, and delirium events associated with calm restless, ICU stay was shortened after the implement of daily interruption therapy and nursing. Conclusion: The application of daily interruption in general ICU is beneficial to their disease recovery, reduce adverse events related with calmness, worthy of clinical attention, but it is imperative to improve the security of condition monitoring and nursing

Feasibility and effect of para-right bundle branch pacing in patients with atrial fibrillation and complete atrioventricular block

Background: Chronic right ventricular apex (RVA) pacing can induce negative clinical effects. The aim of the present study was to compare RVA pacing with para-right bundle branch (para-RBB) pacing in terms of electrocardiogram (ECG) and echocardiographic (ECHO) features. Methods: Forty-one consecutive persistent atrial fibrillation patients with an indication for permanent pacing treatment due to complete atrioventricular block were randomly assigned to receive a screw-in lead either in the RVA (n = 22) or at the para-RBB (n = 19). Para-RBB pacing leads were located according to the RBB potential recorded by electrophysiology catheter. ECG was recorded before and after implantation. All patients underwent the pacemaker pro­gramming at 1 day, 6 months, 12 months and 24 months after implantation. ECHO examina­tion was performed during follow-up at 6, 12 and 24 months after implantation to assess the heart function and synchronism. Results: There was no significant difference in pacing lead parameters between para-RBB pacing group and RVA pacing group. Compared with RVA pacing group, the para-RBB pacing group obtained a narrower QRS complex, more synchronic ventricular systole, and less nega­tive effect on heart function (p < 0.05). Conclusions: Para-RBB pacing has potential clinical benefits and may be a physiological pacing site.

Instruct and Extract: Instruction Tuning for On-Demand Information Extraction

Large language models with instruction-following capabilities open the door to a wider group of users. However, when it comes to information extraction - a classic task in natural language processing - most task-specific systems cannot align well with long-tail ad hoc extraction use cases for non-expert users. To address this, we propose a novel paradigm, termed On-Demand Information Extraction, to fulfill the personalized demands of real-world users. Our task aims to follow the instructions to extract the desired content from the associated text and present it in a structured tabular format. The table headers can either be user-specified or inferred contextually by the model. To facilitate research in this emerging area, we present a benchmark named InstructIE, inclusive of both automatically generated training data, as well as the human-annotated test set. Building on InstructIE, we further develop an On-Demand Information Extractor, ODIE. Comprehensive evaluations on our benchmark reveal that ODIE substantially outperforms the existing open-source models of similar size. Our code and dataset are released on https://github.com/yzjiao/On-Demand-IE.Comment: EMNLP 202