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Vision based runway identification using ‘marked or unmarked terrain’ image sequences captured from a fixed wing unmanned aerial vehicle through onboard stereovision sensor is presented in this paper. An innovative convolutional neural network (CNN) based YOLO-V8 object detection algorithm is used to detect the runway during approach segment of UAV. This deep learning algorithm detects the region of interest in real time and in a computationally efficient manner. The captured unknown road segment or runway image frames are processed and examined for width, length, level and smoothness aspects to qualify as a suitable runway for UAV landings. Also, it is ensured that there are no obstacles, patches or holes on the detected road or runway. Runway start and end threshold lines and regions, touchdown point and runway edge lines are considered as the region of interest. Image processing algorithms are applied on the captured runway or road images to detect strong features in the region of interest. Feature detector based image processing algorithm with stereo vision constraint is used to establish the relation between unmanned aerial vehicle's center of gravity and detected runway feature points. Image processing algorithms like hough line detection, RANSAC, Oriented FAST and Rotated BRIEF (ORB), median filters, morphological methods are applied to extract terrain features. Based on the detected runway orientation and position with respect to UAV position. An automatic landing manoeuvre is performed by UAV autopilot to land the UAV on intended touchdown point on runway computed through detected feature points.

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This paper presents autonomous landing controller design of unmanned aerial vehicles (UAVs). Feedback linearization approach with anti windup scheme is designed as autonomous landing controller. Anti windup basically controls the integrator component accumulation in the autopilot design and restricts the output within saturation limits. Autonomous landing of a fixed wing UAV consists of approach, glideslope and flare phases. During approach, aerial vehicle aligns itself with runway and reduces its lateral deviations with respect to runway central line. In glide slope phase, aerial vehicle maintains a fixed flight path angle and descends with a constant sink rate. In flare phase, aerial vehicle follows an exponential trajectory and descends with a lower sink rate which keeps reducing further as it goes to lower altitudes. Flare controller is designed with integrator and antiwindup scheme is used to handle the controller output within saturation limits. Landing is primarily a longitudinal mode operation but due to disturbances and coupling lateral and directional modes also gets activated. In this paper pitch angle, roll angle and yaw angle nonlinear dynamic equations are linearized to obtain the control commands in terms of elevator deflection, aileron deflection and rudder deflections. Similarly total velocity of aerial vehicle being an important parameter is controlled using thrust command. A first order linearized model of velocity is used to obtain thrust control command. Autonomous landing of UAV with feedback linearization controller and anti windup scheme is simulated with Six-DOF model of AE2 UAV. The algorithm is implemented with wind disturbances to show the autonomous landing performance of UAV.

In recent times, solid lipid nanoparticles (SLNs) have emerged as a promising dosage innovation. However, the concept remains in its infancy as it relates to organ and site-specific drug delivery challenges. The objective of the study design is to develop SLN with better pharmaceutical characterization and anti-inflammatory property as compared to marketed formulation. To enhance the permeability across the skin, Tofacitinib citrate (TFC)-loaded SLNs were developed, and the microemulsification technique was utilized in conjunction with the triglyceride lipid Tripalmitin (TP). N-trimethyl chitosan (NTC) a chemically derived chitosan possessing potential benefits, is added as a release retardant, and Brij-35, a surfactant, is added to develop the microemulsion. The Box-Behnken design suggested the development and characterization of seventeen SLNs for particle size, entrapment efficiency (EE), and percentage drug release. All those SLNs were in the size range of 185–380 nm. Greater amounts of TP combined with an appropriate quantity of Brij-35 possessed the highest EE of 71.2%, according to the results. To identify the optimal SLN, the results are analyzed, and polynomial equations and half-normal plots are constructed. The optimal formulation was developed to contain a level of 1.28% for TP, 5.6 mg of NTC, and 0.33% Brij-35. The optimized SLN was then evaluated for surface morphology, zeta estimation, attenuated total reflectance, differential scanning calorimetry, and X-ray diffraction. Information ascertained that the optimized SLN had an average particle size of 193.7 nm and a zeta magnitude of 4.1 mV. In-vivoanti-inflammatory activity was observed in complete freunds adjuvant (CFA) solution treated Wistar rats. The data showed satisfactory and significant value from the optimized formulation; which is further validated and tested by analysis of variance.

Auto landing of unmanned aerial vehicles with reactive collision avoidance is presented in this paper. Unmanned aerial vehicle follows approach phase, glide slope phase and flare phases during auto landing maneuver. This auto landing unmanned aerial vehicle encounters another unmanned aerial vehicle which comes across its glide path and poses a threat of possible collision. The other vehicle is termed as an ‘obstacle’ for the auto landing vehicle. The prediction logic is used to compute the minimum distance between two vehicles. If the minimum predicted distance is less than a predefined safety distance then the possible collision is predicted. The collision cone based approach is used to compute the aiming point. The velocity vector is deflected using guidance strategies to reach the aiming point. The differential geometric guidance is used to reach the aiming point in the available time to go. The auto landing vehicle senses the obstacle approaching towards it through stereo vision sensing and performs a collision avoidance maneuver. During collision avoidance maneuver, auto landing vehicle changes its speed as well as direction. However, the speed reduction is subjected to stall speed of the vehicle. The non cooperative scenario is considered where only the auto landing vehicle performs the collision avoidance and the obstacle follows its nominal path. The cooperative scenario is also considered where both the vehicles perform collision avoidance maneuver and rejoin their respective path post collision avoidance maneuver. The six degree of freedom model of both the unmanned aerial vehicles is used for simulation.

Pancreatic cancer is the seventh most prevalent cause of mortality globally. Since time immemorial, plant-derived products have been in use as therapeutic agents due to the existence of biologically active molecules called secondary metabolites. Flavonoids obtained from plants participate in cell cycle arrest, induce autophagy and apoptosis, and decrease oxidative stress in pancreatic cancer. The present study involves network pharmacology-based study of the methanolic leaf extract of Trema orientalis (MLETO) Linn. From the high-resolution mass spectrometry (HRMS) analysis, 21 nucleated flavonoids were screened out, of which only apigeniflavan was selected for further studies because it followed Lipinski’s rule and showed no toxicity. The pharmacokinetics and physiochemical characteristics of apigeniflavan were performed using the online web servers pkCSM, Swiss ADME, and ProTox-II. This is the first in silico study to report the efficiency of apigeniflavan in pancreatic cancer treatment. The targets of apigeniflavan were fetched from SwissTargetPrediction database. The targets of pancreatic cancer were retrieved from DisGeNET and GeneCards. The protein–protein interaction of the common genes using Cytoscape yielded the top five hub genes: KDR, VEGFA, AKT1, SRC, and ESR1. Upon molecular docking, the lowest binding energies corresponded to best docking score which indicated the highest protein–ligand affinity. Kyoto Encyclopaedia of Genes and Genomes (KEGG) database was employed to see the involvement of hub genes in pathways related to pancreatic cancer. The following, pancreatic cancer pathway, MAPK, VEGF, PI3K–Akt, and ErbB signaling pathways, were found to be significant. Our results indicate the involvement of the hub genes in tumor growth, invasion and proliferation in the above-mentioned pathways, and therefore necessitating their downregulation. Moreover, apigeniflavan can flourish as a promising drug for the treatment of pancreatic cancer in future.

ABSTRACTPiscidin-1 possesses significant antimicrobial and cytotoxic activities. To recognize the primary amino acid sequence(s) in piscidin-1 that could be important for its biological activity, a long heptad repeat sequence located in the region from amino acids 2 to 19 was identified. To comprehend the possible role of this motif, six analogs of piscidin-1 were designed by selectively replacing a single isoleucine residue at a d (5th) position or at an a (9th or 16th) position with either an alanine or a valine residue. Two more analogs, namely, I5F,F6A-piscidin-1 and V12I-piscidin-1, were designed for investigating the effect of interchanging an alanine residue at a d position with an adjacent phenylalanine residue and replacing a valine residue with an isoleucine residue at another d position of the heptad repeat of piscidin-1, respectively. Single alanine-substituted analogs exhibited significantly reduced cytotoxicity against mammalian cells compared with that of piscidin-1 but appreciably retained the antibacterial and antiendotoxin activities of piscidin-1. All the single valine-substituted piscidin-1 analogs and I5F,F6A-piscidin-1 showed cytotoxicity greater than that of the corresponding alanine-substituted analogs, antibacterial activity marginally greater than or similar to that of the corresponding alanine-substituted analogs, and also antiendotoxin activity superior to that of the corresponding alanine-substituted analogs. Interestingly, among these peptides, V12I-piscidin-1 showed the highest cytotoxicity and antibacterial and antiendotoxin activities. Lipopolysaccharide (12 mg/kg of body weight)-treated mice, further treated with I16A-piscidin-1, the piscidin-1 analog with the highest therapeutic index, at a single dose of 1 or 2 mg/kg of body weight, showed 80 and 100% survival, respectively. Structural and functional characterization of these peptides revealed the basis of their biological activity and demonstrated that nontoxic piscidin-1 analogs with significant antimicrobial and antiendotoxin activities can be designed by incorporating single alanine substitutions in the piscidin-1 heptad repeat.

An effective reactive collision avoidance algorithm is presented in this paper for unmanned aerial vehicles (UAVs) using two simple inexpensive pinhole cameras. The vision sensed data, which consists of the azimuth and elevation angles at the two camera positions, is first processed through a Kalman filter formulation to estimate the position and velocity of the obstacle. Once the obstacle position is estimated, the collision cone philosophy is used to predict the collision over a short period of time. In case a collision is predicted, steering guidance commands are issued to the vehicle to steer its velocity vector away using the nonlinear differential geometric guidance. A new cubic spline based post-avoidance merging algorithm is also presented so that the vehicle rejoins the intended global path quickly in a smooth manner after avoiding the obstacle. The overall algorithm has been validated using the point mass model of a prototype UAV with first-order autopilot delay. Both extended Kalman filtering (EKF) and unscented Kalman filtering (UKF) have been experimented. Both are found to be quite effective. However, performance of UKF was found to be better than EKF with minor compromise in computational efficiency and hence it can be a better choice. Note that because of two cameras, stereovision signature gets associated with optical flow signature thereby making the overall signature quite strong for obstacle position estimation. This leads to a good amount of success as compared to the usage of a single pinhole camera, results of which has been published earlier.

Background: Piperine is a type of amide alkaloid that exhibits pleiotropic properties like antioxidant, anticancer, anti-inflammatory, antihypertensive, hepatoprotective, neuroprotective and enhancing bioavailability and fertility-related activities. Piperine has the ability to alter gastrointestinal disorders, drug-metabolizing enzymes, and bioavailability of several drugs. The present review explores the available clinical and preclinical data, nanoformulations, extraction process, structure–activity relationships, molecular docking, bioavailability enhancement of phytochemicals and drugs, and brain penetration properties of piperine in the prevention, management, and treatment of various diseases and disorders. Main body: Piperine provides therapeutic benefits in patients suffering from diabetes, obesity, arthritis, oral cancer, breast cancer, multiple myeloma, metabolic syndrome, hypertension, Parkinson's disease, Alzheimer’s disease, cerebral stroke, cardiovascular diseases, kidney diseases, inflammatory diseases, and rhinopharyngitis. The molecular basis for the pleiotropic activities of piperine is based on its ability to regulate multiple signaling molecules such as cell cycle proteins, anti-apoptotic proteins, P-glycoprotein, cytochrome P450 3A4, multidrug resistance protein 1, breast cancer resistance protein, transient receptor potential vanilloid 1 proinflammatory cytokine, nuclear factor-κB, c-Fos, cAMP response element-binding protein, activation transcription factor-2, peroxisome proliferator-activated receptor-gamma, Human G-quadruplex DNA, Cyclooxygenase-2, Nitric oxide synthases-2, MicroRNA, and coronaviruses. Piperine also regulates multiple signaling pathways such as Akt/mTOR/MMP-9, 5′-AMP-activated protein kinase-activated NLR family pyrin domain containing-3 inflammasome, voltage-gated K+ current, PKCα/ERK1/2, NF-κB/AP-1/MMP-9, Wnt/β-catenin, JNK/P38 MAPK, and gut microbiota. Short conclusion: Based on the current evidence, piperine can be the potential molecule for treatment of disease, and its significance of this molecule in the clinic is discussed. Graphical abstract:

Naturally occurring cationic antimicrobial peptides (AMPs) mostly adopt α-helical structures in bacterial membrane mimetic environments. To explore the design of novel β-sheet AMPs, we identified two short cationic amphipathic β-strand segments from the crystal structure of the innate immune protein, MyD88. Interestingly, of these, the 10-residue arginine–valine-rich synthetic MyD88-segment, KRCRRMVVVV (M3), exhibited β-sheet structure when bound to the outer membrane Gram-negative bacterial component, LPS. Isothermal titration calorimetric data showed that M3 bound to LPS with high affinity, and the interaction was hydrophobic in nature. Supporting these observations, computational studies indicated strong interactions of multiple and consecutive valine residues of M3 with the acyl chain of LPS. Moreover, M3 adopted nanosheet and nanofibrillar structure in 25% acetonitrile/water and isopropanol, respectively. M3 showed substantial antibacterial activities against both Gram-positive and Gram-negative bacteria which it appreciably retained in the presence of human serum and physiological salts. M3 was non-hemolytic against human red blood cells and non-cytotoxic to 3T3 cells up to 200 μM and to mice in vivo at a dose of 40 mg/kg. Furthermore, M3 neutralized LPS-induced pro-inflammatory responses in THP-1 cells and rat bone marrow-derived macrophages. Consequently, M3 attenuated LPS-mediated lung inflammation in mice and rescued them (80% survival at 10 mg/kg dose) against a lethal dose of LPS. The results demonstrate the identification of a 10-mer LPS-interacting, β-sheet peptide from MyD88 with the ability to form nanostructures and in vivo activity against LPS challenge in mice. The identified M3-template provides scope for designing novel bioactive peptides with β-sheet structures and self-assembling properties.