Nanoscale science and nanotechnology have been demonstrated to have great potential in providing novel and improved solutions to many grand challenges facing agriculture and society today and in the ...future. This review highlights some of the most promising and important nanotechnology applications in agriculture; and recommends several strategies for advancing the best scientific and technological knowledge presently being examined. In addition, implications for human and environmental health, and technical, financial and capacity-related challenges as they relate to developing countries are identified. Finally, some suggested mechanisms for partnerships and collaborations are also identified and suggested.
Smartphone-based point-of-care testing (POCT) is rapidly emerging as a potential alternative to the traditional laboratory-based diagnostic testing owing to economic considerations and availability ...of medical equipment especially in resource-limited areas. A smartphone, combined with a biosensor and other related accessories, can offer high accuracy and sensitivity for medical testing. Moreover, the ubiquity of smartphone has propelled the development considerably, and accordingly research in recent years has shown promising progress in POCT. Here, we used samples (blood, urine, sweat, saliva and tears) of liquid biopsy as the standard for classification of smartphone-based POCT devices, considering that these samples contain multiple biomarkers of serious diseases. The colorimetric, fluorescent, brightfield, and electrochemical methods were utilized to examine these samples. We performed a comprehensive review of the development of smartphone-based POCT devices over the past two years (2017–2018) and assessed their relative merits and drawbacks. Based on the progress of POCT development, it illustrates that the various technological and economical requirements are urgent and tremendous. The tendency of high-quality, low-cost smartphone-based POCT devices, feature of biosensors (paper-based sensor, flexible device, microfluidic chip, et al.) currently widely used in POCT and recommendations of future works were summarized.
•The samples of liquid biopsy as the standard for classification of point of care testing since those samples often contain multiple important biomarkers.•The development of smartphone-based POCT devices in last two years (2017–2018) was comprehensively reviewed.•Novel directions of POCT application and research were proposed.
Pancreatic cancer is a malignancy with poor prognosis and high mortality. The recent increase in pancreatic cancer incidence and mortality has resulted in an increased number of studies on its ...epidemiology. This comprehensive and systematic literature review summarizes the advances in the epidemiology of pancreatic cancer, including its epidemiological trends, risk factors, risk prediction models, screening modalities, and prognosis. The risk factors for pancreatic cancers can be categorized as those related to individual characteristics, lifestyle and environment, and disease status. Several prediction models for pancreatic cancer have been developed in populations with new-onset diabetes or a family history of pancreatic cancer; however, these models require further validation. Despite recent progress in pancreatic cancer screening, the quantity and quality of related studies are also unsatisfactory, especially with respect to the identification of high-risk populations and development of effective screening modality. Apart from the populations with familial genetic risk and those at a high risk of sporadic pancreatic cancer, risk factors such as new-onset diabetes may be a new direction for timely intervention. We hope this work will provide new ideas for further prevention and treatment of pancreatic cancer.
•Both incidence and mortality rate of pancreatic cancer has increased in recent years.•Risk factors for PDAC include individual characteristics, lifestyle and environment, and disease status.•The current established modality for effective early detection of PDAC is lacking.•Development of effective biomarkers predicting the prognosis are in high demand.
•Berberine could improve 3×Tg AD mice’s cognitive function.•Berberine could attenuate the hyperphosphorylation of tau.•Berberine could promote autophagic clearance of tau.
Berberine is a natural ...isoquinoline alkaloid isolated from the Rhizoma coptidis. Recent advances in research throw more lights of its beneficial role towards Alzheimer’s disease (AD), including promoting β-amyloid (Aβ) clearance, as well as inhibiting Aβ production in the triple-transgenic mouse model of Alzheimer’s disease (3×Tg AD). However, it remains unclarified if berberine has an effect on tau pathology. According to our study, berberine did not only significantly improve 3×Tg AD mice’s spatial learning capacity and memory retentions, but also attenuated the hyperphosphorylation of tau. via modulating the activity of Akt/glycogen synthase kinase-3β and protein phosphatase 2A. Moreover, berberine reduced the level of tau through an autophagy-based route. It promoted autophagic clearance of tau by enhancing the activity of autophagy via the class III PI3K/beclin-1 pathway. Thus, our results suggest that berberine could mitigate cognitive decline by simultaneously targeting the hyperphosphorylation of tau and the autophagic clearance of tau in AD mice. These findings strongly support berberine as a potential drug candidate for AD.
A research in extending bandwidth of the visible light communication (VLC) system that uses phosphorescent white LED has been reported in this letter. Slow response of the phosphorescent component ...limits the modulation bandwidth of white LED to the lower MHz range. In this letter, we present a post-equalization circuit that contains two passive equalizers and one active equalizer. With blue-filtering and the post-equalization circuit, a bandwidth of 151 MHz has been achieved in our VLC system, which allows OOK-NRZ data transmission up to 340 Mb/s. The VLC link operates at 43 cm using a single one Watt white LED, and the bit-error-ratio was below 2×10 -3 , which is within the forward error correction limit.
With a rapid improvement of smartphone hardware and software, especially complementary metal oxide semiconductor (CMOS) cameras, many optical biosensors based on smartphone platforms have been ...presented, which have pushed the development of the point-of-care testing (POCT). Imaging-based and spectrometry-based detection techniques have been widely explored via different approaches. Combined with the smartphone, imaging-based and spectrometry-based methods are currently used to investigate a wide range of molecular properties in chemical and biological science for biosensing and diagnostics. Imaging techniques based on smartphone-based microscopes are utilized to capture microscale analysts, while spectrometry-based techniques are used to probe reactions or changes of molecules. Here, we critically review the most recent progress in imaging-based and spectrometry-based smartphone-integrated platforms that have been developed for chemical experiments and biological diagnosis. We focus on the analytical performance and the complexity for implementation of the platforms.
A dynamic path-planning algorithm is proposed for routing unmanned air vehicles (UAVs) in order to track ground targets under path constraints, wind effects, and obstacle avoidance requirements. We ...first present the tangent vector field guidance (TVFG) and the Lyapunov vector field guidance (LVFG) algorithms. We demonstrate that the TVFG outperforms the LVFG as long as a tangent line is available between the UAV's turning circle and an objective circle, which is a desired orbit pattern over a target. Based on a hybrid version of the TVFG and LVFG, we then derive a theoretically shortest path algorithm with UAV operational constraints given a target position and the current UAV dynamic state. This algorithm has the efficiency of the TVFG when UAV is outside the standoff circle and the ability to follow the path via the LVFG when inside the standoff circle. In addition we adopt point-mass approximation of the target state probability density function (pdf) for target motion prediction by exploiting road network information and target dynamics as well as obstacle avoidance strategies. Overall, the proposed technical approach is practical and competitive, supported by solid theoretical analysis on several aspects of the algorithm performance. With extensive simulations we show that the tangent-plus-Lyapunov vector field guidance (T+LVFG) algorithm provides effective and robust tracking performance in various scenarios, including a target moving according to waypoints or a random kinematics model in an environment that may include obstacles and/or winds.
Antibodies against tumor‐associated antigens have been found in serum of patients with various types of cancers and may serve as biomarkers for early detection of gastric cancer as well. This ...systematic review aims to give an overview about known autoantibodies and their diagnostic value in gastric cancer. We conducted a systematic literature search in two databases to identify studies which performed serological testing for autoantibodies in gastric cancer patients and controls. Data on study characteristics and results were extracted independently by two reviewers. Overall, 39 articles reporting the detection of 34 different autoantibodies met the inclusion criteria for this review. The most common antibody detection method was enzyme‐linked immunosorbent assay and the most frequently assessed autoantibody was anti‐p53, which was tested in 13 studies. Most antibodies were assessed in only one study and only few authors have evaluated the diagnostic value of combinations of multiple autoantibodies. For single autoantibodies, specificity was generally very high (median: 99.15%), but sensitivity was mostly rather low (median: 12.35%). For some autoantibody combinations, substantially higher sensitivity at reasonably high levels of specificity could be achieved. Development of extended and optimized multimarker panels of autoantibodies might be a promising approach for gastric cancer early detection.
Fecal immunochemical tests (FITs) for hemoglobin are increasingly recommended and used in colorectal cancer (CRC) screening. We aimed to provide a detailed assessment of the sensitivity of FIT ...according to type and subsite of neoplasms in a true screening setting. A quantitative FIT (FOB Gold, Sentinel Diagnostics, Milano, Italy) was applied prior to colonoscopy by 3,466 participants of the German screening colonoscopy program. Subsite specific sensitivity for various types of colorectal neoplasms was derived by comparing FIT results with findings at screening colonoscopy. The most advanced finding at colonoscopy was CRC, advanced adenoma, and nonadvanced adenoma in 29, 354 and 686 cases, respectively. Per‐adenoma sensitivity for large advanced adenomas (>1 cm) strongly varied by location (p < 0.001): cecum: 0/14 (0%), ascending colon and right flexure: 11/43 (26%), transverse colon and left flexure: 2/14 (14%), descending colon: 7/12 (58%), sigmoid colon: 47/92 (51%), rectum: 14/39 (36%). By contrast, the FIT detected all of 5 proximal CRC and 23 out of 24 (96%) distal CRCs, whereas per‐adenoma sensitivity of both proximal (17/259, 7%) and distal nonadvanced adenomas (20/237, 8%) essentially equaled the false positivity rate among those without neoplasms (152/2,397, 6%). In conclusion, we found a very large gradient of subsite specific FIT sensitivity for detecting large advanced adenomas ranging from 0% for advanced adenomas located in the cecum to >50% for those located in the descending or sigmoid colon. By contrast, FIT sensitivity was uniformly excellent for CRC and uniformly poor for nonadvanced adenomas, regardless of their location.
What's new?
Fecal immunochemical tests for hemoglobin are increasingly used in colorectal cancer (CRC) screening, but detailed diagnostic performance characteristics according to the type and location of neoplasms are still lacking. Here, the authors aimed to provide a detailed sensitivity assessment in a true screening setting. Among 3,466 participants to the German screening colonoscopy program, the authors found that sensitivity was close to 100% for CRC and 0% for non‐advanced adenomas at any location. In contrast, site‐specific sensitivity for large advanced adenomas varied from 0% (cecum) to >50% (distal colon). The results provide an important empirical basis for further enhancing CRC screening.
The Moderate Resolution Imaging Spectroradiometer (MODIS) instruments currently operate onboard the National Aeronautics and Space Administration (NASA's) Terra and Aqua spacecraft, launched on ...December 18, 1999 and May 4, 2002, respectively. MODIS has 36 spectral bands, among which 20 are reflective solar bands (RSBs) covering a spectral range from 0.412 to 2.13 μm. The RSBs are calibrated on orbit using a solar diffuser (SD) and an SD stability monitor and with additional measurements from lunar observations via a space view (SV) port. Selected pseudo-invariant desert sites are also used to track the RSB on-orbit gain change, particularly for short-wavelength bands. MODIS views the Earth surface, SV, and the onboard calibrators using a two-sided scan mirror. The response versus scan angle (RVS) of the scan mirror was characterized prior to launch, and its changes are tracked using observations made at different angles of incidence from onboard SD, lunar, and Earth view (EV) measurements. These observations show that the optical properties of the scan mirror have experienced large wavelength-dependent degradation in both the visible and near infrared spectral regions. Algorithms have been developed to track the on-orbit RVS change using the calibrators and the selected desert sites. These algorithms have been applied to both Terra and Aqua MODIS Level 1B (L1B) to improve the EV data accuracy since L1B Collection 4, refined in Collection 5, and further improved in the latest Collection 6 (C6). In C6, two approaches have been used to derive the time-dependent RVS for MODIS RSB. The first approach relies on data collected from sensor onboard calibrators and mirror side ratios from EV observations. The second approach uses onboard calibrators and EV response trending from selected desert sites. This approach is mainly used for the bands with much larger changes in their time-dependent RVS, such as the Terra MODIS bands 1-4, 8, and 9 and the Aqua MODIS bands 8 and 9. In this paper, the algorithms of these approaches are described, their performance is demonstrated, and their impact on L1B products is discussed. In general, the shorter wavelength bands have experienced a larger on-orbit RVS change, which, in general, are mirror side and detector dependent. The on-orbit RVS change due to the degradation of band 8 can be as large as 35% for Terra MODIS and 20% for Aqua MODIS. Vital to maintaining the accuracy of the MODIS L1B products is an accurate characterization of the on-orbit RVS change. The derived time-independent RVS, implemented in C6, makes an important improvement to the quality of the MODIS L1B products.
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