Jetting-based bioprinting:process,dispense physics,and applications

Jetting-based bioprinting facilitates contactless drop-on-demand deposition of subnanoliter droplets at well-defined positions to control the spatial arrangement of cells,growth factors,drugs,and biomaterials in a highly automated layer-by-layer fabrication approach.Due to its immense versatility,jetting-based bioprinting has been used for various applications,including tissue engineering and regenerative medicine,wound healing,and drug development.A lack of in-depth understanding exists in the processes that occur during jetting-based bioprinting.This review paper will comprehensively discuss the physical considerations for bioinks and printing conditions used in jetting-based bioprinting.We first present an overview of different jetting-based bioprinting techniques such as inkjet bioprinting,laser-induced forward transfer bioprinting,electrohydrodynamic jet bioprinting,acoustic bioprinting and microvalve bioprinting.Next,we provide an in-depth discussion of various considerations for bioink formulation relating to cell deposition,print chamber design,droplet formation and droplet impact.Finally,we highlight recent accomplishments in jetting-based bioprinting.We present the advantages and challenges of each method,discuss considerations relating to cell viability and protein stability,and conclude by providing insights into future directions of jetting-based bioprinting.

ORDER-PICKING OPTIMIZATION FOR AUTOMATED PICKING SYSTEM WITH PARALLEL DISPENSERS

Based on the characteristics of parallel dispensers in automated picking system, an order-picking optimization problem is presented. Firstly, the working principle of parallel dispensers is introduced, which implies the time cost of picking each order is influenced by the order-picking sequence. So the order-picking optimization problem can be classified as a dynamic traveling salesman problem （TSP）. Then a mathematical model of the problem is established and an improved max-min ant system （MMAS） is adopted to solve the model. The improvement includes two aspects. One is that the initial assignment of ants depends on a probabilistic formula instead of a random deployment; the other is that the heuristic factor is expressed by the extra picking time of each order instead of the total. At last, an actual simulation is made on an automated picking system with parallel dispensers. The simulation results proved the optimization value and the validity of improvement on MMAS.

Fluid-based Slotting Optimization for Automated Order Picking System with Multiple Dispenser Types

Slotting strategy heavily influences the throughput and operational cost of automated order picking system with multiple dispenser types, which is called the complex automated order picking system （CAOPS）. Existing research either focuses on one aspect of the slotting optimization problem or only considers one part of CAOPS, such as the Low-volume Dispensers, to develop corresponding slotting strategies. In order to provide a comprehensive and systemic approach, a fluid-based slotting strategy is proposed in this paper. The configuration of CAOPS is presented with specific reference to its fast-picking and restocking subsystems. Based on extended fluid model, a nonlinear mathematical programming model is developed to determine the optimal volume allotted to each stock keeping unit （SKU） in a certain mode by minimize the restocking cost of that mode. Conclusion from the allocation model is specified for the storage modules of high-volume dispensers and low-volume dispensers. Optimal allocation of storage resources in the fast-picking area of CAOPS is then discussed with the aim of identifying the optimal space of each picking mode. The SKU assignment problem referring to the total restocking cost of CAOPS is analyzed and a greedy heuristic with low time complexity is developed according to the characteristics of CAOPS. Real life application from the tobacco industry is presented in order to exemplify the proposed slotting strategy and assess the effectiveness of the developed methodology. Entry-item-quantity （EIQ） based experiential solutions and proposed-model-based near-optimal solutions are compared. The comparison results show that the proposed strategy generates a savings of over 18% referring to the total restocking cost over one-year period. The strategy proposed in this paper, which can handle the multiple dispenser types, provides a practical quantitative slotting method for CAOPS and can help picking-system-designers make slotting decisions efficiently and effectively.

ACCELERATED LIFE TEST STUDIES OF NEW COATED DISPENSER CATHODES

The life of impregnated Ba-W cathodes with a new construction have been evaluated using an accelerated life test at three different temperatures (1170℃,1130℃,1090℃) and constant current density (2A/cm^2).According to the relationship of life with operating temperatures,an accelerated equation has been set up.The cathode life at normal operating temperature is deducted based on the accelerated equation.The results show that life of the novel cathode exceeds 190,000 hour at a current density of 2A/cm^2.

A NEW Ba-W DISPENSER CATHODE IMPREGNATED WITH BARIUM YTTERBATE

A new kind of Ba-W dispenser cathode impregnated with barium ytterbate has been deve-loped.It has good properties;high coefficient of secondary emission,strong ability of resisting oxygenpoisoning,high thermionic emission current density and more uniform emission on the cathode surface.The cathode is suitable for using as an electron emitter for microwave tubes,especially magnetrons.

IMPROVEMENT OF THE PERFORMANCE OF THE DISPENSER CATHODE WITH Re AS A MIDDLE LAYER

A new type of dispenser cathode with dual-layer (Os-W/Re) is developed. The cathode coated with Os-W/Re shows better emission performance than the cathode coated with Os-W alloy. X-ray Photoelectron Spectroscopy (XPS) spectra demonstrate that ternary alloy coating (Os-W-Re) formed on the surface of the cathode with dual-layer (Os-W/Re) after full activation is the major reason why it has better emission than the cathode with Os-W alloy. The surface of each variety of the cathode is characterized with Scanning Electron Microscope (SEM) before and after activation: the emitting surface of the cathode with Os-W alloy after ageing appeared non-adherence (flaking) in localized areas, which is one of the reasons for non-uniform emission. However, the surface of the cathode with dual-layer (Os-W/Re) does not present film peeling under the same conditions. Thus it ensures better emission uniformity and functional reliability for the dispenser cathode.

H_2 Output Feedback Control for Airborne Dispenser Uncertain Generalized System

The problem of H2 output feedback control for generalized system with structural uncertainties is studied using linear matrix inequality approach. A sufficient condition Of linear matrix inequality is presented such that the closed-loop system is stable and satisfies H2 performance for all admissible uncertainties. Furthermore, the solution of the controller is given. An H2 output feedback controller is designed in the airborne dispenser pitch channel, and the simulation results show that the controller is effective.

RCS Reduction of Airborne Dispenser

The radar cross section (RCS) of dispenser and its components is computed by graphical electromagnetic computing (GRECO) method, which bases on physical optics (PO) method. A satisfied agreement is gotten between computed and measured results outdoor. The results show that the main scattering source of the dispenser is the mirror reflecting of the body; in the most crucial nose-on region, the nose mirror reflecting plays important role; the corner reflecting is important to the fins' RCS. The corresponding measures to reduce dispenser's RCS are proposed. It is indicated that to reduce RCS, shaping should be adopts first, while aerodynamic characteristics and stealth characteristics should be considered synthetically during the design of dispenser.

HIGH EMISSION PERFORMANCE IMPREGNATED DISPENSER CATHODE

In order to obtain higher emission performance than that of a traditional M-type cathode, we have developed a new type impregnated dispenser cathode. The new cathode is impregnated with a new active substance with molar ratio of 26BaO·29SrO·8Sc2O3 ·7CaO·Al2O3 . This paper introduces the emission performance, surface active material, and work function of the new cathode. At 1100℃B , the DC current density and pulse current density are 30.6±1.0 A/cm2 and 171.6±2.8 A/cm2 , respectively, 2.1 and 5.4 times of that of an M-type cathode. The work function of the new cathode is 1.668± 0.002 eV. High concentration O-Al-Sc-Sr-Ba and O-Al-Sc-Ba are found in the pores and at pore edges, respectively. By comparing the emission performances and surface characteristics of as-polished and as-cleaned cathodes, it is proposed that, the emission around pore ends forms the major part of the total emission for the new cathodes.

Impact of Training of Dispensers on Case Management of Acute Respiratory Tract Infections at Community Pharmacies in Pakistan

Purpose: To evaluate the impact of training of dispensers on the process of case management of ARI at community pharmacies in context to history taking and provision of advice working at community pharmacies in Islamabad, Pakistan. Method: A randomized, controlled, blinded intervention study was designed and implemented. Before the implementation of intervention, a baseline study was performed to assess the process of case management for ARI at community pharmacies. The study population included all community pharmacy outlets in Islamabad. After data collection, data was analyzed. The result of the study revealed that the overall process of disease management of ARI at community pharmacies in Pakistan is not satisfactory. Pharmacies of Islamabad which were visited in pre intervention phase (118) were divided into two geographical regions A (intervention) and B (control). From which thirty pharmacies were selected randomly from each region. The targeted group of the interventions was drug sellers. Keeping in view the results of the base line study an educational intervention was designed to improve the case management of ARI at community pharmacies in Pakistan. Results: No significant difference (p ≤ 0.05) was seen in the process of history taking and advice provision in case of ARI management at community pharmacies between pre and post control groups. On the other hand significant difference in the process of history taking and provision of advice for ARI was observed in the intervention group before and after training. Conclusion: The study has highlighted that improvements in the current dispensing practices at community pharmacies are possible through appropriate educational interventions. The dispensers have the potential to provide fast and low cost healthcare to the masses in the country where the presence of doctors and qualified pharmacist is low;to date they are an untapped and underutilized source in the country.

The Impact of Jams on the Vending Robot

This study aims to identify the causes of sensor jams and its impact on the operation of vending machines. The vending machine is a machine that automatically dispenses products such as drinks, tickets, sandwiches and biscuits, by inserting change or credit card into the machine. This technological feat is due to the advent of sensors. A sensor is a part of the measurement chain, it receives the quantity to be measured and provides information directly linked to this quantity. However, these vending robots are faced with malfunctions linked to sensor jams. The identification of the jam phenomenon was possible thanks to the inspection and monitoring of the various sensors installed on the vending robot. And Cadence software was used to model, control and locate the jammed sensor(s). The various tests were carried out by setting the robot in motion to better understand the causes of the phenomenon. The jam is therefore the phenomenon which triggers the sensors permanently, which causes the automatic vending robot to stop functioning. And this jam was due to the presence of water droplets on the sensor or dirt. This presence of water droplets on the sensor is linked to an increase in temperature. Controlling the temperature and locating the jammed sensor has made it possible to considerably reduce jamming and its harmful effects on the vending machine robot.

Multi-pulsed intense electron beam emission from velvet,carbon fibers,carbon nano-tubes and dispenser cathodes

The experimental results of studies of four kinds of cathode emitting intense electron beams are demonstrated under multi-pulsed mode based on an experimental setup including two multi-pulse high voltage sources.The tested cathodes include velvet,carbon fibers,carbon nano-tubes （CNTs） and dispenser cathodes.The results indicate that all four are able to emit multi-pulsed beams.For velvet,carbon fiber and CNTs,the electron induced cathode plasma emission may be the main process and this means that there are differences in beam parameters from pulse to pulse.For dispenser cathodes tested in the experiment,although there is a little difference from pulse to pulse for some reason,thermal-electric field emission may be the main process.

Provantis系统Dispense模块在药物非临床安全性评价供试品管理的应用前景

随着我国GLP行业的发展及其与国际接轨的需要,实验室管理及实验数据采集的信息化、网络化的要求日益迫切,供试品管理是GLP评价的源头和关键环节。Dispense模块是Provantis系统用于供试品管理的模块,该模块包含供试品管理的接收、记账、留样、配制和归档等多个流程,能极大地提高供试品管理的科学性、准确性和有效性。本文就Dispense模块的特点、主要流程中的优势以及不足之处进行综述,并展望了Dispense模块在药物非临床评价供试品管理的应用前景。

Pediatric burns due to hot water from water dispenser： a neglected issue that should be highly concerned

Background More and more Chinese drink hot water from water dispensers while many children were scalded due to this change. The present study aimed to propose a feasible strategy for prevention. Methods A retrospective study was conducted for all water dispensers related pediatric burns admitted to Changhai Hospital from January 2005 to December 2009. Results The number of new cases and incidences of pediatric burns due to hot water from water dispensers was significantly increasing year after year. In the total 238 involved cases, 175 cases happened on males and 78.9% were at the age of 1-4 years. The burn areas were mainly located in upper extremities. All water dispensers in the surveyed families had no isolate protection devices and 85.2% of their locations were easy for children to reach. Nearly half of the children were in the same room with their guardians when injured. Total 196 burned children were playing the taps of water dispensers before injured, unfortunately, 80.6% of them have not been stopped until burned. Conclusion As the kind of burns is quite serious and with bad outcome, some recommendations should be followed, such as buying water dispensers with protection devices, keeping children from touching them and so on.

Exploration of Teaching Reform of TCM Dispensing Technology in Higher Vocational Colleges Based on Traditional Chinese Medicine Skills Competition

This paper aims to thoroughly explore the teaching reform of Traditional Chinese Medicine(TCM)dispensing technology in higher vocational colleges,with a focus on the Traditional Chinese Medicine Skills Competition.By analyzing the current teaching status and main challenges of TCM dispensing technology,and aligning with the requirements of the skills competition,a series of detailed and practical teaching reform measures are proposed.These measures are designed to comprehensively improve the teaching quality of TCM dispensing technology in higher vocational colleges,enhance students’practical skills and professional qualities,and ultimately meet the demand for high-quality,skilled talents in the field of TCM.

Microcapillary cell extrusion deposition with picolitre dispensing resolution

Extrusion-based cell deposition has become a prominent technique for expanding bioprinting applications.However,the associated print resolution in the order of nanolitre or above has been a limiting factor.The demand for improving print resolution towards the scale of a single cell has driven the development of precision nozzle extrusion,although the benefits gained remain ambiguous.Here,aided by in situ imaging,we investigated the dynamics of cell organisation through an extrusion-based microcapillary tip with picolitre precision through in-air or immersion deposition.The microcapillary extrusion setup,termed‘Picodis’,was demonstrated by generating droplets of colouring inks immersed in an immiscible medium.Next,using 3T3 fibroblast cells as an experimental model,we demonstrated the deposition of cell suspension,and pre-aggregated cell pellets.Then,the dynamic organisation of cells within the microcapillary tip was described,along with cell ejection and deposition upon exiting the tip opening.The vision-assisted approach revealed that when dispersed in a culture medium,the movements of cells were distinctive based on the flow profiles and were purely driven by laminar fluid flow within a narrow tip.The primary process limitations were cell sedimentation,aggregation and compaction,along with trapped air bubbles.The use of picolitre-level resolution microcapillary extrusion,although it provides some level of control for a small number of cells,does not necessarily offer a reliable method when a specified number of cells are required.Our study provides insights into the process limitations of high-resolution cell ink extrusion,which may be useful for optimising biofabrication processes of cell-laden constructs for biomedical research.

Knowledge,attitude,and practices related to medication errors among nursing professionals:a questionnaire-based study in a tertiary care hospital

Objective:To evaluate the level of understanding(knowledge),beliefs(attitude),and behavior(practice)of staff nurses toward medication errors(MEs).Methods:Self-administered questionnaires were distributed to nursing professionals who had at least 1 year of work experience.Each questionnaire contained 19 items assessing“knowledge,”“attitude,”and“practice”attributes toward MEs.Results:Responses from 47 nursing respondents were included for the final analysis.The mean knowledge score was 3.8±1.1(out of 6);66%and 79%of the respondents had awareness of medication repor ting systems and interventions in preventing MEs,respectively.Lack of adequate knowledge in recognizing MEs(P=0.003),or presuming MEs are not as important enough to be reported(P=0.002),was considered as the major reason for under-repor ting of MEs.Nurses with higher knowledge score were against administration of medication through a different route than that prescribed by the physician(P=0.023),and tried to rectify an ME(P=0.020)and stayed with the patient until an oral medication had been swallowed(P=0.037).Conclusions:The nursing professionals were aware of the ME repor ting system and methods to prevent the occurrence of MEs.They also exhibited a positive attitude and followed optimal practices in controlling MEs.

A Literature Review: Pharmaceutical Care an Evolving Role at Community Pharmacies in Pakistan

The aim of this paper is to highlight the role of pharmaceutical care at community pharmacies in Pakistan. The paper draws on the literature related to current dispensing practices at community pharmacies in developing countries as well as in Pakistan. There are approximately 63,000 community pharmacies in Pakistan, and according to an estimate, 80% of the medicines are being distributed through this channel to majority of the population. They often lack adequate facilities, staffing and equipments. Absence of pharmacists and their roles being performed by the non-qualified personnel working at community pharmacies are a common practice. There are 8102 pharmacists who are categorized as a category, 31,000 pharmacy technicians categorized in B & C category in the country. There is a shortage of pharmacists who could be engaged for ensuring good pharmacy practices. There are only ten percent of the total pharmacists who work at community pharmacies in the country according to the Pharmacy Council of Pakistan. All kind of medicines are freely available irrespective of their status as prescription or over the counter drugs. The paper highlights that the professional role of pharmacist in hospitals and community pharmacies is switching from dispensing and sale of drugs, to patient counselling. But, the concept of pharmaceutical care at community pharmacies has not been acknowledged yet in Pakistan. The process of prescription handling is poor and patients are often treated without a proper prescription. Prescription validation, drug labeling and patient counseling are the missing components in effective patient management at the community pharmacies. The paper concludes that although laws exist, but due to lack of accountability and weak regulatory framework their proper implementation is not witnessed. Moreover, due to lack of research and evidence related to problems in dispensing practices in healthcare system of Pakistan, the counteractive actions for resolving these problems are limited.

Development of non-shrinkable ceramic composites for use in high-power microwave tubes

Al_2O_3–CaO–SiC-based ceramic composites with four different compositions were sintered at 1700℃ for 3 h in an air furnace. The phase analysis, microstructural characterization, and elemental composition determination of the developed composites were performed by X-ray diffraction(XRD), field-emission scanning electron microscopy(FESEM), and energy-dispersive X-ray(EDAX) analysis, respectively. The shrinkage, thermal properties, and electrical resistivity of the composites were also studied. The experimental results showed the effects of adding silicon carbide and calcia to alumina on the thermal, electrical, and shrinkage properties of the resultant composites. Among the four investigated ceramic composites, the one composed of 99 wt% alumina, 0.5 wt% CaO, and 0.5 wt% SiC exhibited the best characteristics for use as a potting material in a dispenser cathode of a microwave tube. The material exhibited slight expansion instead of shrinkage during drying or firing. Other properties of the composite powder, such as its thermal properties and electrical resistivity, were comparable to those of a commercial alumina powder.

Importance of labelling and patient knowledge to ensure proper care during drug dispensing: A case study from a tertiary hospital in Ethiopia

Correct drug labelling is central for ensuring proper drug dispensing and thus for patient safety. Labelling errors may result in adverse health outcomes. The objective of this study was, therefore, to assess the effect of labelling on the quality of drug dispensing and patient knowledge about dispensed drugs in Jimma University model and specialized hospital outpatient Pharmacies. Individual packages with prescribed drugs were examined using pretested questionnaire and observational check lists during the dispensing process. Patients’ knowledge about drugs dispensed to them was assessed at the exit interview using a pretested questionnaire. Out of 743 prescribed drugs, 682 (91.8%) were dispensed to 426 patients. The average labelling score (range from 0 to 6) of dispensed drugs in Model and Outpatient pharmacy was 2.00 (95% CI 1.97 to 2.04) and 1.73 (95% CI 1.6 to 1.8) respectively, with overall average labelling score of 1.90 (95% CI 1.84 to 1.91). The average patient knowledge score (range from 0 t0 5) was 3.45 (95% CI 3.31 to 3.59) and 3.5 (95% CI 3.35 to 3.64) for model and outpatient pharmacy, respectively, while the overall average knowledge score was 3.46 (95% CI 3.37 to 3.57). Major labelling problems were absence of patient’s name and dose followed by frequency of administration, duration of treatment, and the reason for prescription. Literacy status of patients had a significant effect on their knowledge (p 0.05). We recommend that corrective measures targeting both, labelling and patients’ knowledge should be implemented to improve the patients’ safety and drug therapy adherence.