Key Scientific Issues Research Articles

Method to evaluate the quality of herbal medicines based on the dynamic changes of chemical compounds and pharmacological activity

Quality control has been one of the key scientific issues in the modernization of traditional Chinese medicine. This study explored a novel method for quality evaluation of herbal medicines. High-performance liquid chromatography fingerprints and the osteoblast proliferation activity of 18 batches of Achyranthes bidentata, which were prepared with salt, were determined to establish a chromatographic database and an activity database. Correlation analyses of these databases were performed using partial least squares to obtain regression coefficients (positive and negative correlation coefficients). Then, the sums of the products of the positive and negative correlation peak areas and the corresponding coefficients, respectively, were calculated for each sample. The absolute value of the ratios of the sums of the positive and negative products were calculated, our studies showed that this ratio was significantly correlated with the proliferation activity, particularly when the activity was in the best and worst ranges. Therefore, we developed a parameter that was used to evaluate the quality of samples osteoblast proliferation activity. The quality of another ten batches of samples was assessed to verify this method. The results indicated that this method can be used for quality evaluation of herbal medicines according to the dynamic changes in the chemical compounds and activity.

Applications, opportunities and challenges of molecular probes in the diagnosis and treatment of major diseases

Minimally invasive treatment of cancer can significantly reduce surgery risks due to many advantages, such as no laparotomy, small wound and early recovery and so on. Especially, it is suitable for patients who cannot be operated on due to tumor distant metastasis, oldness, weakness, and major organ dysfunction. According to clinical statistics, more than 60% of patients with mid-advanced cancer can be cured by employing minimally invasive surgery. Malignant tumors often show invasive growth and unclear boundary, resulting in partial removal of healthy tissue during surgery, hence postoperative sequelae and dysfunction. In order to carry out minimally invasive surgery and targeted elimination of tumor, the size and location of the tumors must be accurately identified before therapy, which requires the imaging guidance. By using optical molecular imaging, we can find a small tumor less than ~1mm. Therefore, the molecular imaging navigation provides a great opportunity for the development of minimally invasive interventional therapy for cancer. Especially, the cancer specific probes are emerging as one of the key technologies of molecular imaging. Compared with small molecular probes, nanoprobes show longer imaging time, remarkable signal multiplication and drug loading capacity. There, specific nanoprobes become the development direction of the molecular imaging navigation technology. Aiming at accuracy, high efficacy and minimal invasiveness of cancer treatments, we need solve two key scientific issues including identification of tumor boundary and predictability of lymph node metastases, and develop three key technologies including: high accumulation of nanoprobes at tumor sites, high sensitivity of nanoprobes to cancer cells, high precision imaging methods based on nanoprobes. This project will design and construct a variety of safe and efficient nanoprobes and related nanomaterials with independent intellectual property rights. For example, ultra pH (or enzyme)-sensitive fluorescent nanoprobes will be fabricated for the imaging of a broad range of tumours by nonlinear amplification of microenvironment signals. Multifunctional nanoprobes will be developed for simultaneous molecular imaging and interventional therapy of cancer. Fluorescent/ultrasound nanoprobes will be prepared to achieve a bimodal imaging with excellent signal sensitivity and high spatial resolution. Theranostic nanoprobes will be produced for both targeted imaging (diagnosis) and interventional therapy (laser, ultrasound, microwave, radiofrequency or combination etc.). In addition, we will establish a practical and feasible technology platform for large-scale production of nanoprobes, and in vivo and in vitro evaluation systems for the clinical applications of nanoprobes. It is of crucial importance to investigate the biological influence of nanoprobes on cell division, proliferation, apoptosis and signal transduction pathways, assess in vivo transport mechanism across biological barriers, and evaluate biosafety of nanoprobes, such as acute toxicity, long-term toxicity, nervous system toxicity and immunogenicity. Moreover, fluorescence confocal microendoscope and minimally invasive therapeutic devices will be developed based on nanoprobes. Finally, we will assess invasion depth and lymph node metastasis in early gastric cancer, as well as retroperitoneal lymph node metastasis of ovarian cancer by using nanoprobes in combination of fluorescence confocal microendoscope and molecular imaging navigation system. The sensitivity and specificity of molecular imaging nanoprobes are evaluated by using pathology as the gold standard. The precise interventional therapy (photodynamic, photothermal and sonodynamic etc.) will be implemented by irradiating the tumor tissue using laser or ultrasound under the guidance of nanoprobe-enhanced molecular imaging. It is essential to investigate the evaluation methods of therapeutic efficacy. We will explore the synergistic, anti-metastatic and overcoming drug resistance effects of interventional therapy combined with chemotherapy. In conclusion, molecular imaging nanoprobes can be used not only for imaging and diagnosis, but also for the minimally invasive interventional treatments. In particular, the research and application of nanoprobes will promote the development and application of fluorescence confocal microendoscope, molecular imaging navigation systems and minimally invasive interventional therapy systems. This will accelerate the breakthrough in the key technology of major medical equipment. Undoubtedly, the accomplishment of the project would enhance the innovation capability and international competitiveness of China in nanobiomedicine and medical equipment.

Investigation of supramolecular chemical mechanism of traditional Chinese medicine processing

To analyze the research status of traditional Chinese medicine (TCM) processing and key scientific issues to be resolved by using characteristic of TCM biological supramolecules and reaction theories of 'Qi chromatography' to human being, and then put forward the solution countermeasures. Based on the previous explications of theories of the Chinese medicine with supramolecular chemistry as 'Qi chromatograpy', biological supramolecular chemistry theory was used to explain the root of the problem in TCM processing and form the countermeasures for supramolecular chemistry research in the processing of TCM decoction pieces. TCM is a huge complex biological supramolecular body, so the processing of TCM is in view of the processing of huge complex biological supramolecular body. In nature, it is a TCM pharmaceutical technology with chemical changes of the subject and object of biological supramolecular body with or without auxiliary materials, under the condition of high temperature and high humidity. Supramolecular chemistry was throughout the processing of TCM, so the use of supramolecular technology was appropriate in research. TCM decoction pieces were the product of subject and object molecular changes after supramolecular chemistry reaction, with changes in physical and chemical properties of the subject and object molecules, such as bound water overflow, chemical bond rupture, dehydration, carbonization, and reaction with auxiliary materials. Changes in drug property and drug efficacy after processing depended on the degree of subject and object "imprinting template" change, which can be measured by 'Qi chromatography' function of supermolecular imprinting template in human body. In this paper, the research ideas, methods, variety attribution, processing principle, quality standard and clinical application were analyzed to find out the sticking point of the problems, and form the countermeasures with supramolecular chemistry as the core. The processing of TCM is a chemical technology of biological supramolecular body based on the function of supermolecular 'imprinting template' (medical element) of human meridian-viscera, and its reaction products (decoction pieces) showed determinacy when used alone and compatibility when used together, which may constitute a compatible drug delivery system of TCM in clinical application.

Research progresses of resistive random access memory

Resistive random access memory (RRAM) is one of the most promising candidates of next-generation non-volatile memories. Comparing with the traditional floating gate Flash memory, RRAM has advantages in cell structure, operation speed, scalability and ease of 3D integration. In this paper, the RRAM technology is systematically reviewed. The operation principle, technological advantages, development history and fundamental scientific issues of RRAM are introduced. Then several key issues in RRAM are summarized and analyzed in detail, including the materials system, resistive switching mechanism, novel physical effects in RRAM, and 2D/3D integration of RRAM. For the materials system in RRAM, traditional resistive switching films, including solid-electrolyte, complex transition metal oxide, binary metal oxide, are first summarized, following with the analyzing of the recent research progress of the applications of nanowires and 2D materials in RRAM devices. These low-dimensional nanomaterials can be used as the switching dielectrics, planar electrode/nano-electrode/edge electrode and can play active role in the improvement of scalability, switching performances and switching uniformity. Next, we summarize and analyze three resistive switching mechanisms in filamentary RRAM device, i.e. thermochemical mechanism (TCM), electrochemical metallization (ECM) mechanism, valence change mechanism (VCM). Their corresponding SET/RESET switching principles and fundamental electrical characteristics, experimental verifications by transmission electron microscope (TEM) observation are elucidated in detail. Subsequently, based on the resistive switching mechanisms, the novel physical phenomena in RRAM induced by the change of the material microstructure and energy band in the process of resistive switching are elaborated. Three physical effects, including conductance quantization effect, magnetoelectric effect, photoelectric effect, are successively analyzed. At last, considering the integration technology of RRAM, we summarize and analyze the key scientific issues in memory array architecture, 2D/3D integration.

A modified true triaxial apparatus for measuring mechanical properties of sandstone coupled with CO2‐H2O biphase fluid

AbstractMechanical behaviors of rock under biphase or multiphase fluids conditions are key scientific issues currently in geomechanics and geotectonics. In this work, we conducted a series of triaxial experiments using a semipermeable separator method to form a specific composition pressure; we comparatively investigated the mechanical behaviors of sandstone in the conditions of monophase fluids CO2/N2/H2O and biphase fluid CO2‐H2O; and we analyzed the strength, elasticity modulus and brittleness of sandstones at different porous fluid conditions. The results showed that the selective adsorption of mineral compositions of sandstone on CO2/N2/H2O has obvious effects on mechanical behaviors. The linear elastic modulus of CO2‐H2O coupled sandstone was slightly greater than that of H2O‐bearing sandstone, but significantly less than that of CO2‐ or N2‐bearing sandstone. Compared to H2O, CO2 or N2 containing sandstones are mainly subjected to the brittle failure and exhibit no obvious plastic deformation. Overall, the study analyzed the mechanisms of physicochemical interactions of fluid with sandstone minerals from the micro‐scales, and revealed the mechanical mechanism between fluids and mineral particles, and established a new effective stress model of sandstone under CO2‐H2O biphase condition. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd.

A common thread

Public engagement with science can not only inform the public about exciting research, but also help guide the path of the research being conducted. Many researchers are now involved in innovative engagement projects that involve using the skills of artists and makers to help visualise and engage people with their science. Equally, those working in the creative industries such as art, textile and design are becoming interested in how they can use science to inspire their work. Helen Albert speaks to Rhiannon Gregory and Amy Congdon, two young textile designers who are applying their creativity to tackling key scientific issues such as antibiotic resistance and tissue engineering, as well as considering how these techniques could be used to create commercially valuable products. Dr. Lorna Dougan, a physicist and Rhiannon's collaborator also shares her thoughts on art-science collaboration.

ChemInform Abstract: Metal‐Free Carbonaceous Electrocatalysts and Photocatalysts for Water Splitting

AbstractReview: tutorial review; 52 refs.

The climatic impacts of land use and land cover change compared among countries

Land use and land cover change (LULCC) strongly influence regional and global climate by combining both biochemical and biophysical processes. However, the biophysical process was often ignored, which may offset the biogeochemical effects, so measures to address climate change could not reach the target. Thus, the biophysical influence of LULCC is critical for understanding observed climate changes in the past and potential scenarios in the future. Therefore, it is necessary to identify the mechanisms and effects of large-scale LULCC on climate change through changing the underlying surface, and thus the energy balance. The key scientific issues on understanding the impacts of human activities on global climate that must be addressed including: (1) what are the basic scientific facts of spatial and temporal variations of LULCC in China and comparative countries? (2) How to understand the coupling driving mechanisms of human activities and climate change on the LULCC and then to forecasting the future scenarios? (3) What are the scientific mechanisms of LULCC impacts on biophysical processes of land surface, and then the climate? (4) How to estimate the contributions of LULCC to climate change by affecting biophysical processes of land surface? By international comparison, the impacts of LULCC on climate change at the local, regional and global scales were revealed and evaluated. It can provide theoretical basis for the global change, and have great significance to mitigate and adapt to global climate changes.

ChemInform Abstract: Rational Design of Semiconductor‐Based Photocatalysts for Advanced Photocatalytic Hydrogen Production: The Case of Cadmium Chalcogenides

AbstractReview: 213 refs.

Modeling of manufacturing service supply–demand matching hypernetwork in service-oriented manufacturing systems

The supply-demand matching and optimal-allocation of manufacturing resource and manufacturing capability, is always one of the key scientific issues to be addressed and the common objectives to be pursued for various advanced manufacturing systems (AMSs). Especially to the service-oriented manufacturing (SOM) systems (e.g., cloud manufacturing), which is a kind of typical and hot AMSs nowadays , it is extremely difficult to achieve the optimal allocation of large scales of different manufacturing services and the collaboration of manufacturing activities and business among massive manufacturing enterprises (no matter manufacturing service providers and consumers). Thus, under the current environment of social competition and collaboration, the most important challenge is how to integrate a variety of distributed manufacturing resources and capabilities in the form of manufacturing services efficiently and cost-effectively, as well as various demands or manufacturing tasks. In response to this challenge, the concept of supply-demand matching hypernetwork ( Matching_Net ) of manufacturing services in SOM system is put forward firstly in this paper. The proposed Matching_Net is constructed with manufacturing service network ( S_Net ), manufacturing task network ( T_Net ), and hyper-edges between those two networks which are revealing the matchable correlations between each service (supply) and each task (demand). Secondly, by comparing with the input or output information of manufacturing services and tasks from the functional view, the intelligent modeling of Matching_Net is illustrated and divided into those three constituent parts respectively. Finally, the simulation is carried out to validate and verify the proposed models and the modeling method. The model of hypernetwork (i.e., network of networks) is introduced into the supply-demand matching issues in service-oriented manufacturing systems.The concept and model of supply-demand matching hypernetwork ( Matching_Net ) of manufacturing services in SOM system are put forward considering both manufacturing services and manufacturing tasks.By comparing with the input or output information of manufacturing services and tasks, the intelligent modeling flow of Matching_Net is proposed and illustrated.The simulation is carried out to validate and verify the proposed models and the corresponding modeling method.

Controversy in Biology Classrooms-Citizen Science Approaches to Evolution and Applications to Climate Change Discussions.

The biological sciences encompass topics considered controversial by the American public, such as evolution and climate change. We believe that the development of climate change education in the biology classroom is better informed by an understanding of the history of the teaching of evolution. A common goal for science educators should be to engender a greater respect for and appreciation of science among students while teaching specific content knowledge. Citizen science has emerged as a viable yet underdeveloped method for engaging students of all ages in key scientific issues that impact society through authentic data-driven scientific research. Where successful, citizen science may open avenues of communication and engagement with the scientific process that would otherwise be more difficult to achieve. Citizen science projects demonstrate versatility in education and the ability to test hypotheses by collecting large amounts of often publishable data. We find a great possibility for science education research in the incorporation of citizen science projects in curriculum, especially with respect to “hot topics” of socioscientific debate based on our review of the findings of other authors. Journal of Microbiology & Biology Education

Differences in views of experts about their role in particulate matter policy advice: Empirical evidence from an international expert consultation

There is ample scientific evidence of adverse health effects of air pollution at exposure levels that are common among the general population. Some points of uncertainty remain, however. Several theories exist regarding the various roles that experts may play when they offer policy advice on uncertain issues such as particulate matter (PM). Roles may vary according to e.g. the views of the expert on the science-policy interface or the extent to which she/he involves stakeholders. Empirical underpinning of these theories, however, does not exist. We therefore conducted a consultation with experts on the following research question: What are PM experts’ views on their roles when providing policy advice? Q methodology was used to empirically test theoretical notions concerning the existence of differences in views on expert roles. Experts were selected based on a structured nominee process. In total, 31 international PM experts participated. Responses were examined via Principal Component Analysis, and for the open-ended questions, we used Atlas.ti software. Four different expert roles were identified among the participating experts. Main differences were found with respect to views on the need for precautionary measures and on the experts positioning within the science-policy interface. There was consensus on certain issues such as the need for transparency, general disagreement with current policies and general agreement on key scientific issues. This empirical study shows that while most PM experts consider their views on the risks of PM to be in line with those of their colleagues, four distinct expert roles were observed. This provides support for thus far largely theoretical debates on the existence of different roles of experts when they provide policy advice.

The Role of Inclusion Binding Contributions for β-Cyclodextrin Polymers Cross-Linked with Divinyl Sulfone?--A Comment on Morales-Sanfrutos et al. Entitled "Divinyl Sulfone Cross-Linked Cyclodextrin-Based Polymeric Materials: Synthesis and Applications as Sorbents and Encapsulating Agents", Molecules, 2015, 20, 3565-3581.

This commentary reports on a recent scientific study reported in this journal (cf. Molecules 2015, 20(3), 3565–3581). Some key scientific issues that require further explanation and clarification in the former article are as follows: (i) the relationship between the inclusion site accessibility and the level of cross-linking employed are brought into question for the case of α-CD and β-CD cross-linked adsorbent materials; (ii) the binding affinity of the CD/guest complexes were not related to the isotherm parameters for the CD-polymer/guest systems; (iii) the limited molecular level structural characterization of the cross-linked polymer materials; and (iv) the interpretation of the adsorption isotherm results by the authors.

Advantages of population pharmacokinetics and its application in the field of traditional Chinese medicine

The accurate medical treatment is based on the information of the genome, which is the best treatment for the patients. Population pharmacokinetic study can be formulated according to the individual differences of patients to the dose, in the accurate medical model which has a unique advantage. At present, there are many problems such as adverse drug reaction in Chinese traditional medicine, and it is necessary to introduce a group of medicine on the basis of precise medical treatment. However, due to the different characteristics of traditional Chinese medicine and chemical medicine, it is necessary to combine the population pharmacokinetics, genetics and statistical methods to establish a research method which is in line with the characteristics of Chinese medicine. The key scientific problem is to make clear the active components of Chinese medicine metabolism of the drug metabolic enzyme gene, and pay attention to the analysis of the polymorphism of the overall role of drug metabolism enzymes in the human body. Clear key scientific issues and break through the bottleneck, so as to achieve the precise medical treatment, to international.

Key scientific problems on establishing green fertilizer ensurance system

Basic situation and existing problems of chemical fertilizer production and utilization are expounded from the perspective of three aspects of chemical fertilizer dosage, structure and management. It is necessary to balance the essential nutrient elements by adjusting fertilizer nutrient and product type; to realize the sustainable development through fertilizer industrial development planning and policies & regulations management, to implement the development strategy of quality instead of quantity by improving fertilizer efficiency. Establish a green fertilizer ensurance system adapted for Chinese practice through technical measures, management regulations and scientific & technological innovation. Centered the green fertilizer, the key scientific issues need to be paid attention and solved in the process of establishing the green fertilizer ensurance system are put forward. The research on the integration of plant mineral nutrition theory and organic nutrition theory, and further explore on the mechanism of new fertilizer and new product development technology, new technology to innovate traditional basic fertilizer; to strengthen the research on the scientific problems of the transformation of fertilizer, soil and plant, and explore the new technical ways of organic fertilizer, called for establishing the scientific Chinese fertilizer system, which is led by scientists, agricultural experts, industry experts, entrepreneurs and government departments.

Environmental geotechnics in the US region: a brief overview

The present contribution to the Regional Editors themed issue offers a concise yet focused overview of some of the key technical and scientific issues, as well as of current trends and future challenges, related to the broad discipline of environmental geotechnics in the US region. Particular attention is devoted to current policy and societal drivers as well as future professional and research capacity requirements in critical areas such as innovative recycling and improvement of compost, construction and geologic materials; solid waste management, landfilling and geoenvironmental remediation techniques; and crucial geotechnical engineering aspects of renewable energy production, storage and distribution.

Gene therapy for cancer: regulatory considerations for approval.

The rapidly changing field of gene therapy promises a number of innovative treatments for cancer patients. Advances in genetic modification of cancer and immune cells and the use of oncolytic viruses and bacteria have led to numerous clinical trials for cancer therapy, with several progressing to late-stage product development. At the time of this writing, no gene therapy product has been approved by the United States Food and Drug Administration (FDA). Some of the key scientific and regulatory issues include understanding of gene transfer vector biology, safety of vectors in vitro and in animal models, optimum gene transfer, long-term persistence or integration in the host, shedding of a virus and ability to maintain transgene expression in vivo for a desired period of time. Because of the biological complexity of these products, the FDA encourages a flexible, data-driven approach for preclinical safety testing programs. The clinical trial design should be based on the unique features of gene therapy products, and should ensure the safety of enrolled subjects. This article focuses on regulatory considerations for gene therapy product development and also discusses guidance documents that have been published by the FDA.

Human Health Effects of Biphenyl: Key Findings and Scientific Issues.

Background:In support of the Integrated Risk Information System (IRIS), the U.S. Environmental Protection Agency (EPA) has evaluated the human health hazards of biphenyl exposure.Objectives:We review key findings and scientific issues regarding expected human health effects of biphenyl.Methods:Scientific literature from 1926 through September 2012 was critically evaluated to identify potential human health hazards associated with biphenyl exposure. Key issues related to the carcinogenicity and noncancer health hazards of biphenyl were examined based on evidence from experimental animal bioassays and mechanistic studies.Discussion:Systematic consideration of experimental animal studies of oral biphenyl exposure took into account the variety of study designs (e.g., study sizes, exposure levels, and exposure durations) to reconcile differing reported results. The available mechanistic and toxicokinetic evidence supports the hypothesis that male rat urinary bladder tumors arise through urinary bladder calculi formation but is insufficient to hypothesize a mode of action for liver tumors in female mice. Biphenyl and its metabolites may induce genetic damage, but a role for genotoxicity in biphenyl-induced carcinogenicity has not been established.Conclusions:The available health effects data for biphenyl provides suggestive evidence for carcinogenicity in humans, based on increased incidences of male rat urinary bladder tumors at high exposure levels and on female mouse liver tumors. Kidney toxicity is also a potential human health hazard of biphenyl exposure.Citation:Li Z, Hogan KA, Cai C, Rieth S. 2016. Human health effects of biphenyl: key findings and scientific issues. Environ Health Perspect 124:703–712; http://dx.doi.org/10.1289/ehp.1509730

Review of the Metallogenic Regularity of Magnesite Deposits in China

AbstractChina has abundant reserves of magnesite, making it the world's leading source of this strategic mineral. Sparry magnesite is the main type of magnesite deposit, and is easy to exploit. It occurs mainly as the sedimentary‐metamorphic type. Production is centred on eastern Liaoning Province, where a world‐class large to super large magnesite ore processing and production facility has been developed. Hydrothermal metasomatic deposits, associated with ultramafic complexes and eluvial deposits produced by weathering, are two other important types found in China. The Western section of the Bangonghu‐Nujiang metallogenic belt is an important target region for prospecting lake‐sedimentary magnesite deposits. Based on a systematic analysis of material from 62 magnesite production areas, this study investigated the metallogeny of magnesite and delineated 13 magnesite metallogenic belts. Maps were produced showing metallogenic regularities in magnesite deposits, the metallogenic system of the magnesite deposits, and the distribution of the metallogenic belts of Chinese magnesite deposits. It provides a theoretical basis for forecasting the location of potential magnesite resources in China. Finally, it explores some key scientific issues, including the formation processes of ultra magnesite ore‐concentrated areas, and their sources of magnesium.

The Complicate Observations and Multi-Parameter Land Information Constructions on Allied Telemetry Experiment (COMPLICATE).

The Complicate Observations and Multi-Parameter Land Information Constructions on Allied Telemetry Experiment (COMPLICATE) comprises a network of remote sensing experiments designed to enhance the dynamic analysis and modeling of remotely sensed information for complex land surfaces. Two types of experimental campaigns were established under the framework of COMPLICATE. The first was designed for continuous and elaborate experiments. The experimental strategy helps enhance our understanding of the radiative and scattering mechanisms of soil and vegetation and modeling of remotely sensed information for complex land surfaces. To validate the methodologies and models for dynamic analyses of remote sensing for complex land surfaces, the second campaign consisted of simultaneous satellite-borne, airborne, and ground-based experiments. During field campaigns, several continuous and intensive observations were obtained. Measurements were undertaken to answer key scientific issues, as follows: 1) Determine the characteristics of spatial heterogeneity and the radiative and scattering mechanisms of remote sensing on complex land surfaces. 2) Determine the mechanisms of spatial and temporal scale extensions for remote sensing on complex land surfaces. 3) Determine synergist inversion mechanisms for soil and vegetation parameters using multi-mode remote sensing on complex land surfaces. Here, we introduce the background, the objectives, the experimental designs, the observations and measurements, and the overall advances of COMPLICATE. As a result of the implementation of COMLICATE and for the next several years, we expect to contribute to quantitative remote sensing science and Earth observation techniques.