A well-defined diamine from lignin depolymerization mixtures for constructing bio-based polybenzoxazines

The demand for high-performance materials is increasing, and most of these materials are petrol based. Therefore, the development of highly efficient and selective catalytic methods that allow access to industrially relevant polymer building blocks from complex biomass depolymerization mixtures is essential. Here, we report on a robust catalytic strategy to obtain the industrially relevant 4,4′-methylenebiscyclohexanamine (MBCA) from lignin oxidation mixtures and its use for constructing fully bio-based polybenzoxazines. The strategy consists of two challenging catalytic steps: 1) the funneling of lignin-derived bisphenol mixtures into 4,4′-methylenebiscyclohexanol (MBC) and 2) the highly selective amination of MBC with ammonia to obtain MBCA. The renewable polybenzoxazines were prepared from MBCA and phenolic lignin platform chemicals. The most promising, cured poly (S-MBCA), shows high glass transition temperature Tg of 315°C, outstanding thermal stability (T10% = 400°C), and good storage modulus (E′25°C = 3.8 GPa), which is competitive with commercial resins

Customized vibration generator for state of health monitoring of prosthetic implants and pseudo-bionic machine-human feedbacks

Modern industrial, household and other equipment include sophisticated power mechanisms and complicated control solutions that require tighter human-machine-human interactions to form the structures known as cyber-physical-human systems. Their significant parts are human-machine command links and machine-human feedbacks. Such systems are found in medicine, e.g., in orthopedics, where they are important for the operation and functional abilities of orthopedic devices-wheelchair, prosthesis, rehabilitation units, etc. The mentioned feedbacks may be implemented based on the haptic perceptions that requires vibration actuators. In orthopedics, such actuators can be used also for diagnostic purposes. This research brings forward the idea of the use of 3D printing in conjunction with high quality permanent magnets. This allows for the achievement of better efficiency, smaller size, and the developing of actuators individually for particular circumstances. The obtained simulation, experimental data, and data about 3D manufacturing generally confirm the above hypothesis. In particular, the stiffness coefficient of the actuator's membrane and attached mass, which can be changed easily during 3D printing, affects the frequency of maximal power output. Secondly, the 3D manufacturing process is quick, tunable and rather cheap. Finally, an elaboration of the design of the actuator that allows for the real-time modification of stiffness and mass in a program way is planned for future workspublishersversionPeer reviewe

Fully lignocellulose-based PET analogues for the circular economy

Polyethylene terephthalate is one of the most abundantly used polymers, but also a significant pollutant in oceans. Due to growing environmental concerns, polyethylene terephthalate alternatives are highly sought after. Here we present readily recyclable polyethylene terephthalate analogues, made entirely from woody biomass. Central to the concept is a two-step noble metal free catalytic sequence (Cu20-PMO catalyzed reductive catalytic fractionation and Raney Ni mediated catalytic funneling) that allows for obtaining a single aliphatic diol 4-(3-hydroxypropyl) cyclohexan-1-ol in high isolated yield (11.7 wt% on lignin basis), as well as other product streams that are converted to fuels, achieving a total carbon yield of 29.5%. The diol 4-(3-hydroxypropyl) cyclohexan-1-ol is co-polymerized with methyl esters of terephthalic acid and furan dicarboxylic acid, both of which can be derived from the cellulose residues, to obtain polyesters with competitive Mw and thermal properties (Tg of 70–90 °C). The polymers show excellent chemical recyclability in methanol and are thus promising candidates for the circular economy.</p

A combination of experimental and computational methods to study the reactions during a Lignin-First approach

AbstractCurrent pulping technologies only valorize the cellulosic fiber giving total yields from biomass below 50 %. Catalytic fractionation enables valorization of both cellulose, lignin, and, optionally, also the hemicellulose. The process consists of two operations occurring in one pot: (1) solvolysis to separate lignin and hemicellulose from cellulose, and (2) transition metal catalyzed reactions to depolymerize lignin and to stabilized monophenolic products. In this article, new insights into the roles of the solvolysis step as well as the operation of the transition metal catalyst are given. By separating the solvolysis and transition metal catalyzed hydrogen transfer reactions in space and time by applying a flow-through set-up, we have been able to study the solvolysis and transition metal catalyzed reactions separately. Interestingly, the solvolysis generates a high amount of monophenolic compounds by pealing off the end groups from the lignin polymer and the main role of the transition metal catalyst is to stabilize these monomers by transfer hydrogenation/hydrogenolysis reactions. The experimental data from the transition metal catalyzed transfer hydrogenation/hydrogenolysis reactions was supported by molecular dynamics simulations using ReaXFF

188 Re Zoledronic Acid in the Palliative Treatment of Painful Bone Metastases

188Re Zoledronic acid (188Re-ZA) is new radiopharmaceutical which may have advantages over other bone seeking β-emitters due to high radiation energy of 188Re, and metabolic effect of zoledronic acid.In the phase I-II of the study therapeutic dosage of 188Re-ZA was estimated. Pharmacokinetics, dosimetry and safety were assessed in the dose escalation study. Twenty-one (3, 3 and 15) breast and prostate cancer patients with multiple painful bone metastases received 35, 45 and 55 MBq of 188Re-ZA respectively. In the next step 42 new patients were randomized in 2 groups (188Re-ZA in dosage of 45 MBq/kg and 89SrCl2 in dosage of 150 MBq) to assess safety and efficacy of the radiopharmaceuticals, the follow up lasted for 9 weeks.Absorbed dose to the bone marrow is respectively low 0.26±0.06 Gy. The dose escalation study shows that 188Re-ZA the dosage of 55 MBq/kg is safe, no significant hematologic or any other toxicity is observed. 89SrCl2 in a dosage of 150 MBq, as compared to 188Re-ZA in a dosage of 45 MBq/kg demonstrates similar efficacy, but the effect starts faster in 188Re-ZA group. By the end of the follow up some patients demonstrated pain recurrence, this may indicate the need for repeated courses of treatment. Though many patients with widespread bone metastases and the higher base level of alkaline phosphatase were in the 188Re-ZA group, in the majority of cases of both groups stabilization of the disease was achieved and continued for at least two months. Both radiopharmaceuticals demonstrated acceptable safety profile. Although trend in reduction of hemoglobin level was observed, especially in the group of patients with baseline anemia, both radiopharmaceuticals significantly impact on the platelet counts (PLT) only. As it was predicted by dosimetry data, 188Re-ZA in a dose of 45 MBq/kg is safer, by the week 6 the PLT counts in the 188Re-ZA group became almost the same as baseline and even higher in the week 9, while in the 89SrCl2 group in the week 9 PLT counts remained below the baseline; the difference was statistically proven. It seems that patients with breast cancer, in contrast to those with prostate cancer, have benefit (not statistically significant) in overall survival: 20.7 vs 15.6 months regardless dosage or type of radiopharmaceutical

The Russian database of HIV antiretroviral drug resistance

The development of sequencing technologies and bioinformatic analysis made it possible to conduct molecular and epidemiological studies, in which nucleotide sequences of the human immunodeficiency virus (HIV) are used as information added to the patient profile. From a practical perspective, studies of prevalence of HIV drug resistance (HIVDR) are of the highest significance. To promote such studies, different countries use databases that serve as repositories of genetic and epidemiological information. The Russian HIVDR database (https://hivresist.ru/) was created in 2009. Nevertheless, it was characterized by limited applicability for a long time. Since 2021, after the regulatory documents had been revised and updated, the entry of HIVDR research results into the Russian HIVDR database has been mandatory. Therefore, the priority attention has been given to upgrading the database and improving its functional capabilities. Different methods have been developed to enter clinical, epidemiological and genetic data. At the time of this study, the Russian database HIVDR contained 10,626 unique records about patients and 13,126 nucleotide sequences deposited by 10 institutions. The following functions have been provided for data analysis: quality control of the epidemiological and clinical information about a patient, quality control of nucleotide sequences, contamination check, subtyping, detection of DR mutations, identification of viral tropism and generation of standardized reports. The efforts toward further development of the Russian HIVDR database will be focused on designing tools for detection and analysis of molecular clusters, adaptation to routine application for epidemiological surveillance of HIV infection

Research and Design of a Routing Protocol in Large-Scale Wireless Sensor Networks

无线传感器网络，作为全球未来十大技术之一，集成了传感器技术、嵌入式计算技术、分布式信息处理和自组织网技术，可实时感知、采集、处理、传输网络分布区域内的各种信息数据，在军事国防、生物医疗、环境监测、抢险救灾、防恐反恐、危险区域远程控制等领域具有十分广阔的应用前景。 本文研究分析了无线传感器网络的已有路由协议，并针对大规模的无线传感器网络设计了一种树状路由协议，它根据节点地址信息来形成路由，从而简化了复杂繁冗的路由表查找和维护，节省了不必要的开销，提高了路由效率，实现了快速有效的数据传输。 为支持此路由协议本文提出了一种自适应动态地址分配算——ADAR（AdaptiveDynamicAddre...As one of the ten high technologies in the future, wireless sensor network, which is the integration of micro-sensors, embedded computing, modern network and Ad Hoc technologies, can apperceive, collect, process and transmit various information data within the region. It can be used in military defense, biomedical, environmental monitoring, disaster relief, counter-terrorism, remote control of haz...学位：工学硕士院系专业：信息科学与技术学院通信工程系_通信与信息系统学号：2332007115216

Palladium-catalyzed lignin valorization : Towards a lignin-based biorefinery

The work described in this thesis focuses on the cleavage of the β-O-4′ bond, which is the most abundant interunit linkage in the lignin polymer. In the first part, three methods based on palladium catalysis have been developed and their applicability has been verified using lignin model compounds. A transfer hydrogenolysis of the β-O-4′ bond using formic acid as a mild hydrogen donor together with a base. An aerobic oxidation of the benzylic alcohol motif in the β-O-4′ linkage to generate a key intermediate in the cleavage reaction was performed. A redox neutral cleavage of the β-O-4′ bond was accomplished in which no stoichiometric reducing or oxidizing agents were added. In the second part of the thesis, a mechanistic study is presented. The corresponding ketone from a dehydrogenation reaction of the benzylic alcohol motif was identified to be the key intermediate. This ketone and its enol tautomer was found to be responsible for the β-O-4′ bond cleavage reaction under the employed reaction conditions. In the final part of this thesis, the methodologies have been applied to native lignin. The depolymerization reaction was combined with organosolv pulping. This approach was successful, and together with cellulose and hemicellulose, propenyl aryls were generated in excellent yields directly from wood. In this transformation, the lignin derived molecules have been reduced by an endogenous hydrogen donor from the wood