Synthesis and in Vitro Antifungal Activities of Novel Benzamide Derivatives Containing a Triazole Moiety.

The study reported the synthesis and antifungal activities in vitro against six phytopathogenic fungi of 17 novel N-[2-hydroxy-3,3-dimethyl-2-[(1H-1,2,4-triazol-1-yl)methyl]butyl]benzamide derivatives. All the target compounds were synthesized and elucidated by means of MS, high resolution (HR)-MS, IR, (1)H- and (13)C-NMR analysis. The results showed that almost all the derivatives exhibited good activities against each of the tested fungi at the concentration of 50 µg/mL. Among them, 6h displayed excellent activity against Alternaria alternata with the median effective concentration value (EC50) of 1.77 µg/mL, superior to myclobutanil (EC50=6.23 µg/mL), a commercial fungicide with broad-spectrum bioactivities for plant protection and high-efficiency. Compound 6k showed the broadest antifungal spectrum, demonstrating positive activities against the corresponding fungi with EC50 values ranging from 0.98 to 6.71 µg/mL. Furthermore, 6e to 6i revealed good activities against Alternaria solani with EC50 values of 1.90, 4.51, 7.07, 2.00 and 5.44 µg/mL, respectively. The preliminary analysis of structure-activity relationship (SAR) demonstrated that the presence of F or Cl on the benzene ring remarkably improved the activity, while the introduction of 4-OMe or CF3 group decreased the activity in varying degrees. Thus, the present results strongly suggest that N-[2-hydroxy-3,3-dimethyl-2-[(1H-1,2,4-triazol-1-yl)methyl]butyl]benzamide derivatives should be promising candidates for the development of novel antifungal agents in the effective control of phytopathogenic fungi.

Needle Aligned Ultrasound Image-Guided Access Through Dual-Segment Array.

Ultrasound (US) guided access for percutaneous nephrolithotomy (PCNL) is gaining popularity in the urology community as it reduces radiation risk. The most popular technique involves manual image-needle alignment. A misaligned needle however needs to be retracted and reinserted, resulting in a lengthened operation time and complications such as bleeding. These limitations can be mitigated through the co-registration between the US array and needle. The through-hole array concept provides the primary solution, including a hole at the center of the array. Because of the central opening, the image-needle alignment is achieved inherently. Previous literature has described applications that are limited to superficial and intravascular procedures, suggesting that developing a through-hole array for deeper target applications would be a new breakthrough. OBJECTIVE: Here, we present a dual-segment array with a central opening. As the prototype development, two segments of 32-element arrays are combined with an open space of 10 mm in length in between them. METHOD: We conducted phantom and ex-vivo studies considering the target depth of the 80-100 mm range. The image quality and needle visibility are evaluated by comparing the signal-to-noise ratio (SNR), full width at half maximum (FWHM), and contrast-to-noise ratio (CNR) results measured with a no-hole linear array under equivalent conditions. An ex-vivo study is performed using porcine kidneys with ceramic balls embedded to evaluate the needle access accuracy. RESULTS AND CONCLUSION: The mean needle access error of 20 trials is found to be 2.94 ±1.09 mm, suggesting its potential impact on realizing a simple and intuitive deep US image-guided access.

Large Area Kidney Imaging for Pre-transplant Evaluation using Real-Time Robotic Optical Coherence Tomography.

Optical coherence tomography (OCT) is a high-resolution imaging modality that can be used to image microstructures of human kidneys. These images can be analyzed to evaluate the viability of the organ for transplantation. However, current OCT devices suffer from insufficient field-of-view, leading to biased examination outcomes when only small portions of the kidney can be assessed. Here we present a robotic OCT system where an OCT probe is integrated with a robotic manipulator, enabling wider area spatially-resolved imaging. With the proposed system, it becomes possible to comprehensively scan the kidney surface and provide large area parameterization of the microstructures. We verified the probe tracking accuracy with a phantom as 0.0762±0.0727 mm and demonstrated its clinical feasibility by scanning ex vivo kidneys. The parametric map exhibits fine vasculatures beneath the kidney surface. Quantitative analysis on the proximal convoluted tubule from the ex vivo human kidney yields highly clinical-relevant information.

Intraoperative laparoscopic photoacoustic image guidance system in the da Vinci surgical system.

This paper describes a framework allowing intraoperative photoacoustic (PA) imaging integrated into minimally invasive surgical systems. PA is an emerging imaging modality that combines the high penetration of ultrasound (US) imaging with high optical contrast. With PA imaging, a surgical robot can provide intraoperative neurovascular guidance to the operating physician, alerting them of the presence of vital substrate anatomy invisible to the naked eye, preventing complications such as hemorrhage and paralysis. Our proposed framework is designed to work with the da Vinci surgical system: real-time PA images produced by the framework are superimposed on the endoscopic video feed with an augmented reality overlay, thus enabling intuitive three-dimensional localization of critical anatomy. To evaluate the accuracy of the proposed framework, we first conducted experimental studies in a phantom with known geometry, which revealed a volumetric reconstruction error of 1.20 ± 0.71 mm. We also conducted an ex vivo study by embedding blood-filled tubes into chicken breast, demonstrating the successful real-time PA-augmented vessel visualization onto the endoscopic view. These results suggest that the proposed framework could provide anatomical and functional feedback to surgeons and it has the potential to be incorporated into robot-assisted minimally invasive surgical procedures.

A-SEE: Active-Sensing End-effector Enabled Probe Self-Normal-Positioning for Robotic Ultrasound Imaging Applications.

Conventional manual ultrasound (US) imaging is a physically demanding procedure for sonographers. A robotic US system (RUSS) has the potential to overcome this limitation by automating and standardizing the imaging procedure. It also extends ultrasound accessibility in resource-limited environments with the shortage of human operators by enabling remote diagnosis. During imaging, keeping the US probe normal to the skin surface largely benefits the US image quality. However, an autonomous, real-time, low-cost method to align the probe towards the direction orthogonal to the skin surface without pre-operative information is absent in RUSS. We propose a novel end-effector design to achieve self-normal-positioning of the US probe. The end-effector embeds four laser distance sensors to estimate the desired rotation towards the normal direction. We then integrate the proposed end-effector with a RUSS system which allows the probe to be automatically and dynamically kept to normal direction during US imaging. We evaluated the normal positioning accuracy and the US image quality using a flat surface phantom, an upper torso mannequin, and a lung ultrasound phantom. Results show that the normal positioning accuracy is 4.17 ± 2.24 degrees on the flat surface and 14.67 ± 8.46 degrees on the mannequin. The quality of the RUSS collected US images from the lung ultrasound phantom was equivalent to that of the manually collected ones.

Autonomous Scanning Target Localization for Robotic Lung Ultrasound Imaging.

Under the ceaseless global COVID-19 pandemic, lung ultrasound (LUS) is the emerging way for effective diagnosis and severeness evaluation of respiratory diseases. However, close physical contact is unavoidable in conventional clinical ultrasound, increasing the infection risk for health-care workers. Hence, a scanning approach involving minimal physical contact between an operator and a patient is vital to maximize the safety of clinical ultrasound procedures. A robotic ultrasound platform can satisfy this need by remotely manipulating the ultrasound probe with a robotic arm. This paper proposes a robotic LUS system that incorporates the automatic identification and execution of the ultrasound probe placement pose without manual input. An RGB-D camera is utilized to recognize the scanning targets on the patient through a learning-based human pose estimation algorithm and solve for the landing pose to attach the probe vertically to the tissue surface; A position/force controller is designed to handle intraoperative probe pose adjustment for maintaining the contact force. We evaluated the scanning area localization accuracy, motion execution accuracy, and ultrasound image acquisition capability using an upper torso mannequin and a realistic lung ultrasound phantom with healthy and COVID-19-infected lung anatomy. Results demonstrated the overall scanning target localization accuracy of 19.67 ± 4.92 mm and the probe landing pose estimation accuracy of 6.92 ± 2.75 mm in translation, 10.35 ± 2.97 deg in rotation. The contact force-controlled robotic scanning allowed the successful ultrasound image collection, capturing pathological landmarks.

Effect of chitosan molecular weight on zein-chitosan nanocomplexes: Formation, characterization, and the delivery of quercetagetin.

The impacts of chitosan with different molecular weight on the formation mechanism, structural characteristics and encapsulating properties of the zein-chitosan nanocomplexes were investigated. The results of dynamic light scattering showed that the mean size of nanocomplexes was increased and became more highly positive charge as the molecular weight of chitosan was increased. Circular dichroism indicated that the secondary structure of zein changed after its combination of chitosan. XRD confirmed that quercetagetin was successfully encapsulated into the nanocomplexes, and FTIR revealed that hydrogen bonding and hydrophobic interaction were the main forces acting among the zein, quercetagetin, and chitosan molecules. The optimized zein-Que-LCH (low molecular weight chitosan) nanocomplexes were relatively small (309 nm), positively charged (+42.5 mV), and had a high entrapment efficiency (94.9%). Moreover, encapsulation of quercetagetin within the nanocomplexes extended its half-life by 3.84- and 2.98- folds during the photo- and thermal-degradation measurements, and effectively modulated its release under simulated gastrointestinal conditions.

[Determination of geniposidic acid and chlorogenic acid in male flowers and related products of Eucommia ulmoides by reversed-phase high performance liquid chromatography].

A simple and rapid high performance liquid chromatographic method has been developed for the determination of geniposidic acid and chlorogenic acid in the male flowers and related products of Eucommia ulmoides. Two components were separated by a Shim-pack VP-ODS column (150 mm x4.6 mm, 5 [microm) with a mobile phase of methanol-water-acetic acid (24 :75: 1, v/v) at a flow rate of 1 mL/min, column temperature of 30 93 and detection wavelength of 240 nm. Under the chromatographic conditions mentioned above, the method performance, such as the number of theoretical plate, resolution, trailing etc have all reached required level. The linear ranges were 0. 025 - 0. 400 g/L for geniposidic acid and 0. 075 - 1. 200 g/L for chlorogenic acid, with the correlation coefficients of 0. 999 7 and 0. 999 9, respectively. The average recoveries were 100. 2% and 100. 5%, and the relative standard deviations (RSDs) were 1. 47% and 1. 49% respectively. The minimum detection limits were 0. 02 microg/L for geniposidic acid, and 0. 06 microg/L for chlorogenic acid. The method developed has demonstrated the characteristics of simple mobile phase composition, short retention, good resolution, high repeatability and precision. It is suitable for the determination of the two compounds in the male flowers of E. ulmoides and related products.