Present Technical Challenges Research Articles

Harvesting Composite Arterial and Vein Grafts from Deep Inferior Epigastric Artery and Vein: A Safe Five-Step Method of Preparation.

As the use of stacked flaps and options for autologous breast reconstruction increase, the level of complexity in autologous breast reconstruction has risen. Frequently, these reconstruction types present technical challenges such as vessel mismatches and short pedicle length. In this study, the authors introduce their five steps of harvesting composite deep inferior epigastric artery (DIEA) and deep inferior epigastric vein (DIEV) grafts to overcome such challenges. The authors performed a retrospective review of patients who underwent microvascular reconstruction using DIEA/DIEV grafts from 2012 to 2020. The grafts were harvested using the five steps, as follows: step 1, a transverse, paramedian skin incision was made at the level of suprapubic crease; step 2, an oblique fasciotomy was made on the lateral rectus border; step 3, DIEA/DIEV vessels were identified and exposed past the confluence of two venae comitantes; step 4, DIEA/DIEV grafts were harvested while sparing motor nerves; and step 5, fascial closure was performed. A total of 40 DIEA/DIEV grafts were used in 25 patients (lumbar artery perforator flaps, n = 25; lateral thigh flaps, n = 1; superficial inferior epigastric artery flaps, n = 12; and flap salvage, n = 2) for breast reconstruction. The average time of harvest was 28 minutes, and there were two flap losses. In the authors' experience, DIEA/DIEV grafts can be safely harvested and used in flaps with short pedicles and small vessel size. Although the authors' experience was limited to breast reconstruction, the DIEA/DIEV grafts can be used for other types of reconstruction, especially for head and neck reconstruction.

Fast and high-yield loading of a D2 magneto-optical trap of potassium from a cryogenic buffer-gas beam

We demonstrate the direct loading of a D$_2$ MOT of potassium-39 atoms from a cryogenic buffer gas beam source. We load $10^8$ atoms in a 10 ms pulse, with no degradation in performance up to a 10 Hz repetition rate. Observed densities reach $\sim10^{11}$ atoms/cm$^3$ in a single pulse, achieved with no sub-Doppler cooling or transverse compression. This system produces an ideal starting point for ultracold atom experiments where high experimental repetition rates are desirable and initial high densities are critical. Extension to other atomic species (e.g., refractory metals) that present technical challenges to high-yield production using oven-based sources is straightforward.

Physician-Modified Endografts Versus Chimney/Snorkel for Ruptured and Symptomatic Juxtarenal and Paravisceral Aneurysms in the Vascular Quality Initiative

Ruptured and symptomatic juxtarenal and paravisceral aneurysms present technical challenges during endovascular repair. We sought to compare physician modification and fenestrated (PMEG) versus chimney/periscope/snorkel (CHIMPS) repair techniques for the treatment of ruptured and symptomatic paravisceral and juxtarenal aortic aneurysms (r/sPJAA). Patients in the thoracic and complex endovascular aneurysm module of the Vascular Quality Initiative (VQI) national registry undergoing CHIMPS and PMEG for r/sPJAA were included. Patients who underwent thoracic aneurysm repair with only celiac intervention or who had coverage or occlusion only of one renal or visceral branch vessel were excluded. One-year mortality was the primary outcome. Secondary outcomes included peri- and postoperative endoleak, hospital and ICU length of stay, reintervention, and other local and systemic complications. A total of 81 CHIMPS and 47 PMEG patients were identified. Patients undergoing PMEG were more frequently symptomatic, had a history of CHF and were taking aspirin, statin and P2Y12 antiplatelet medications. Patients undergoing CHIMPS presented more frequently with rupture. There was no significant survival advantage for CHIMPS over PMEG patients (P=0.5). There were no apparent long-term differences in the numbers of endoleaks or in the rates of subsequent reinterventions between the two groups. It does not appear that the procedure type (CHIMPS versus PMEG) is associated with postoperative survival in patients with r/sPJAA. Not surprisingly, survival is associated with postoperative complications, particularly myocardial infarction and intestinal ischemia. Further research should evaluate reasons for failure to rescue from and the impact of postoperative complications on the postoperative survival after endovascular repair of r/sPJAA.

P.154 Subcutaneous intrathecal catheter and port implants for administration of Nusinersen in patients with Spinal Muscular Atrophy

Background: Until recently, no effective treatment was available for spinal muscular atrophy (SMA). In 2017, Health Canada approved intrathecal Nusinersen a medication that prevents degeneration of the motor neurons in the spinal cord. The administration is intrathecally most commonly via lumbar puncture (LP) to have a direct effect on the motor neurons of the spinal cord. Many older patients with SMA and concomitant spinal deformities present technical challenges to access the thecal sac. Different routes have been described for delivery of the medication whoever these techniques may require sedation, are associated with radiation exposure, and demand experience personnel. Methods: A new surgical technique has been proposed to overcome these obstacles by combining two Health Canada approved devices: 1) an intrathecal catheter designed for intrathecal baclofen pumps and 2) an implantable subcutaneous port designed for intravascular medication administration Results: We describe the technical nuances and outline the clinical outcomes of six patients with complex spine deformities who have undergone such an implant for administration of Nusinersen. Conclusions: We discuss the benefits of the procedure which includes: 1) administration in the outpatient setting without sedation, 2) avoidance of costly imaging and experienced personnel, and 3) placement of the catheter in the cervicothoracic junction.

Robotic Surgery for Complicated Diverticular Disease.

Diverticular disease is common, and increasing in prevalence worldwide. The treatment for acute and chronic diverticular disease has a huge clinical and economic burden. Surgery is standard for complicated diverticulitis, and there are several benefits to using robotic surgery in these cases. Complicated diverticular disease can result in fistula, fibrosis, and deranged anatomy, which present technical challenges to the surgeon. Understanding and anticipating these anatomical challenges is key to successful surgery. While fears of conversion in complicated cases may stop surgeons from using traditional laparoscopic surgery, robotic surgery is especially promising for enhancing dexterity, visualization, and facilitating completely minimally invasive surgery in these complicated cases. In this chapter, we review end-to-end technical strategies of robotic colorectal surgery for complicated diverticular disease, including cases with colovesicular, colovaginal, and colocutaneous fistulae.

Percutaneous Chevron and Akin (PECA) Osteotomies for Severe Hallux Valgus Deformity With Mean 3-Year Follow-up.

Patients with severe hallux valgus deformity present technical and operative challenges with high rates of recurrence and residual deformity. The clinical and radiologic outcomes of percutaneous surgery for severe hallux valgus are not known. A retrospective review of consecutive patients with a hallux valgus angle (HVA) >40 degrees or intermetatarsal angle (IMA) >20 degrees who underwent third-generation percutaneous chevron and Akin osteotomy (PECA) for hallux valgus deformity correction. Between December 2012 and August 2019, 59 feet in 50 patients underwent PECA. Preoperative and follow-up radiographic data were available for 53 feet (89.8%). Postoperative clinical patient-reported outcome measures and satisfaction results were available for 51 feet (86.4%). The mean clinical and radiographic follow-up was 3.1 years and the mean postoperative Manchester-Oxford Foot Questionnaire Index score was 15.1. There was a statistically significant improvement (P < .001) in both IMA and HVA following surgery (IMA 17.5-5.1 degrees; HVA 44.1-11.5 degrees). All patients reported they were satisfied with their outcome, with 76.8% reporting they were highly satisfied. The hallux valgus recurrence rate was 7.5%. Percutaneous surgery for severe hallux valgus deformity can achieve a large deformity correction, patient satisfaction, and quality of life, with reasonable rates of residual deformity and low rates of recurrence. Level IV, case series.

A toolbox for studying respiratory viral infections using air-liquid interface cultures of human airway epithelial cells

Submerged cultures of primary human airway epithelial cells or human airway epithelial cell lines have been a mainstay of airway epithelial biology research for decades due to their robust in vitro proliferative capacity, relatively low maintenance culture conditions, and clinically translatable results to nasal or bronchial brushings. With the development and improvement of air-liquid interface (ALI) cultures of human airway epithelial cells, such cultures have been considered superior to immortalized cell lines and primary cell monolayers, as such cultures effectively recapitulate in vivo epithelial architecture and cell types. Although ALI culture growth protocols are well-established and widely available, many researchers have avoided their use, as ALI cultures not only take longer to grow but also present technical challenges and limitations that make in vitro intracellular and structural assays taxing. Challenges arise relating to their complex structure, requirements for air exposure, the constraints of transwell growth apparatus, and interference in assays caused by mucus secretion. Although few publications briefly describe technical adaptations for some assays, there is still considerable trial and error required for researchers to establish consistent and reliable assay adaptations, often becoming a deterrent for pursuing mechanistic investigation. We have created a user-friendly toolbox detailing comprehensive protocols for numerous techniques and assay adaptations, particularly focusing on respiratory virus infections. By expanding the repertoire of ALI culture-adapted in vitro assays, we hope to facilitate the widespread adoption of this valuable culture system for mechanistic investigations of respiratory viral infections or other epithelial-pathogen models.

Development and evaluation of a method to define a tibial coordinate system through the fitting of geometric primitives

ABSTRACT Coordinate system definition is a critical element of biomechanical modeling of the knee, and cases of skeletal trauma present major technical challenges. This paper presents a method to define a tibial coordinate system by fitting geometric primitives to surface anatomy requiring minimal user input. The method presented here utilizes a conical fit to both the tibial shaft and femoral condyles to generate independent axes forming the basis of a tibial coordinate system. Definition of the tibial axis showed high accuracy when shape fitting to ≥50 mm of shaft with <3° of angular variation from the axis obtained using the full tibia. Repeatability and reproducibility of the axis was compared using intraclass correlation coefficients which showed excellent intra- and inter-observer agreement across cases. Additionally, shape fitting to the distal femoral condyles showed high accuracy compared to the reference axis established automatically through identifying the medial and lateral epicondyles (<4°). Utilizing geometric primitives to estimate functional axes for the tibia and femur removes reliance on anatomical landmarks that can be displaced by fracture or inaccurately identified by observers. Furthermore, fitting of such primitives provides a more complete understanding of the true bony anatomy, which cannot be done through simple landmark identification.

Laparoscopic repair of giant Morgagni hernia by direct suturing with V-Loc.

Morgagni hernias present technical challenges. The laparoscopic approach for repair was first described in 1992; however, as these hernias are uncommon in adult life, few data exist on the optimal method for surgical management. The purpose of this study was to analyze a method for laparoscopic repair of Morgagni giant hernias using laparoscopic primary closure with V lock (Medtronic, Covidien). This case series describes a method of laparoscopic Morgagni hernia repair using primary closure. In all patients, a laparoscopic transabdominal approach was used. The content of the hernia was reduced into the abdomen, and the diaphragmatic defect was closed with a running laparoscopic suture using a self-fixating suture. Clips were placed at the edges of the suture to secure the pledged sutures to both the anterior and posterior fascia. Demographic data such as BMI and operative and postoperative data were collected. Retrospectively collected data for 9 patients were analyzed. There were 1 (11.1%) males and 8 (88.8%) females. The median BMI was 29.14±52 kg/m2. The median operative time was 80±25 minutes. There were no intraoperative complications or conversions to open surgery. Patients began a fluid diet on the first postoperative day and were discharged after a median hospital stay of 3±1.87 days. In a median follow-up of 36 months, we did not observe any recurrences. Transabdominal laparoscopic approach with primary closure of the diaphragmatic defect is a viable approach for the repair of Morgagni hernia. In our experience, the use of laparoscopic transabdominal suture fixed to the fascia allowed the closure of the defect laparoscopically with minimal tension on the repairs.

Growing Picochlorum oklahomensis in Hydraulic Fracturing Wastewater Supplemented with Animal Wastewater

Hydraulic fracturing is used to enhance oil and gas extraction from tight shale formations and generates millions of gallons of wastewater which needs to be cleaned up prior to disposal or reuse. The current technologies used for the management of this wastewater present technical, economic, and environmental challenges. Hence, the main objective of this study was to examine the potential of algal remediation of hydraulic fracturing wastewater (PW) as an alternative method. Considering that PW contains very low concentration of the nutrients needed for algae growth PW supplemented with animal wastewater (AW-PW) was also examined. Biomass production capacity, average biomass productivity, and specific growth rate of the microalgae strain used in the study, Picochlorum oklahomensis, were 1.87 g L−1, 268 mg L−1 day−1, and 0.35 day−1, respectively, when grown in PW. Complete nitrate, ammonia, and phosphate removal could be achieved by growing algae in PW. Supplementation of PW with animal wastewater enhanced biomass production (1.87–2.40 g L−1) and lipid content (15–25% wt) in the produced algal biomass. A mathematical model with a correlation coefficient of greater than 0.94 was developed to describe the growth kinetics of algae grown in AW-PW.

Prospects for a Highly Electric Road Transportation Sector in the USA

This review explores the transportation implications of key scenarios for deep decarbonization. While electrification of transportation is not the only action that will be needed to reach climate-change goals, it is one necessary step. This review provides an overview of technologies available for electrification of light-, medium-, and heavy-duty vehicles, the infrastructure required to support electrification, and policy options to accelerate the transition to a cleaner transportation future. Climate studies have shown that as greenhouse gas (GHG) emissions continue rising, aggressive action is needed to achieve deep decarbonization in the USA and worldwide. Transportation is the largest source of GHG emissions in the USA, and one of the largest worldwide. Experts agree that electrifying road transportation is essential to avoiding the worst impacts of climate change. Recent advances in electric vehicle (EV) technology are making electrification viable. Automakers are quickly increasing the number and diversity of commercially available EV models, and consumer awareness of EV technology is slowly growing. Studies show that policymakers can effectively accelerate transportation electrification through tax incentives, regulations, and other policy tools. All credible pathways for achieving deep decarbonization rely on complete or near-complete electrification of passenger vehicles. Advances in EV technology have made this goal feasible from a technical standpoint, though much more needs to be done to achieve rapid electrification in practice. Prospects for electrifying medium- and heavy-duty vehicles are improving, but the high mileage and heavy load requirements of these vehicles present technical challenges. Moreover, achieving widespread electrification of road transportation will require considerable expansion of EV infrastructure (e.g., charging networks), as well as upgrades to existing electric grids. Policymakers can support rapid electrification through actions including tax rebates and other incentives that encourage consumers to purchase EVs, regulations that prioritize electrification of vehicles serving transportation network companies (TNCs), and increased public investment in EV infrastructure and research.

Challenges in Pretreatment/Treatment of Oil in Water Emulsions for Oil Waste Management in the Context of Sustainable Development

The purpose of the article is to present practical, technical and ecological challenges in the pretreatment/treatment technologies of spent oil waste that are oil-in-water emulsion systems containing high volumes of water difficult to be temporary stored. A set of experimental tests on representative oil-in-water spent emulsions have been realized based on a set of treatment screening criteria so that any oil-waste producer/holder can use them to find best pretreatment solutions preventing on-site oil waste generation and preserving in the same time depletion of non-renewable natural resources by recovery of valuable components in the context of sustainable development.

Gastric Bypass Prior to Simultaneous Pancreas-Kidney Transplantation for Optimization of Diabetic Management

Morbid obesity is a relative contraindication for abdominal organ transplantation. Obese patients present technical challenges intra-operatively and are at increased risk of post-operative complications. Bariatric surgery has been shown to be more effective than conventional weight loss strategies in morbidly obese patients, however, current literature is limited to the kidney transplant population. Here were present a case report of a patient with morbid obesity who underwent a laparoscopic Roux-en-Y gastric bypass prior to simultaneous pancreas kidney transplantation.

Outcomes of Bridge Plating Versus Standard Fixation in Geriatric Ankle Fractures

Category:Ankle, TraumaIntroduction/Purpose:Ankle fractures represent one of the most common injuries encountered by foot and ankle specialists. Internal fixation of the lateral malleolus can be achieved by several different techniques, most commonly by lag screw and neutralization plating. However, ankle fractures in older patients often present technical challenges as osteoporotic bone is more commonly encountered which may require bridge plating techniques. This study compares outcomes in patients over age 50 years who underwent ORIF of the lateral malleolus with either a bridge plate or lag screw and neutralization plate technique.Methods:This retrospective study evaluated 56 patients with closed ankle fractures, aged over 50 years who underwent open reduction internal fixation of the lateral malleolus. These were divided into two groups: 36 patients had fixation with one or more lag screws and a neutralization plate, and 20 patients had fixation with a bridge plate technique. Fractures were stabilized with lag screw fixation when feasible, while bridge plating was utilized in patients where lag screw fixation was not possible. SF-36 scores were attained at a minimum one-year post-op. Final radiographs and complications were recorded.Results:The lag group had a mean age of 63 years, 17% men, 61% with syndesmotic screw fixation, and 56% with medial malleolus fixation. The bridge group had a mean age of 65 years, 15% men, 60% with syndesmotic screw fixation, and 70% with medial malleolus fixation. At minimum one-year, SF-36 physical component summary score was 74.2 ± 19.4 in the lag group vs 63.2 ± 24.8 in the bridge plate group (p=0.049). The SF-36 mental component summary score was 89.2 ± 12 in the lag group vs 75.5 ± 22.7 in the bridge plate group (p=0.009). One patient in each group required return to the OR for irrigation and debridement for infection. No patients experienced fixation failure and all fractures demonstrated union on final radiograph.Conclusion:In the present study of patients over age 50 years who underwent ORIF of an ankle fracture, as compared with bridge plating, lag screw and neutralization plating is associated with superior one-year SF-36 physical and mental summary scores with similar rates of complications. However, additional research is needed to determine to what degree this difference is causative or correlative with confounding variables as fixation technique was not found to be an independent predictor of SF-36 outcomes in this small cohort.

High power CW YAG laser weldability of dissimilar Ti to Ni metal plates through beam shift

Incompatibilities of thermo-physical-mechanical as well as metallurgic properties between dissimilar Ti and Ni metals present technical challenges to their fusion joining. In this manuscript, using a high power continuous wave (CW) YAG laser, a direct butt welding of Ti and Ni plates was performed with a relatively large beam offset from the contact interface between two base metals (BMs) toward either side of the BMs. As a result, a large amount of rapidly solidified non-equilibrium solid solution occurred in the main fusion zone (FZ); while the total amount of prior intermetallic compounds (IMCs) such as Ti2Ni, Ni3Ti and NiTi significantly decreased, most of which were primarily located as a band (less than 200 μm wide) along one of the fusion interfaces with the BMs. When the laser beam was shifted 0.5 mm toward the Ni side, the toughness of the FZ was sufficiently improved, leading to a crack-free joint. In this study, the microstructures, chemical compositions, and microhardness in the laser-welds thus obtained were examined to learn the influences of beam offset on laser weldability of Ti to Ni metals.

Wide-Angle Coronary Bifurcation Stenotic Lesions Treated With One Drug-Eluting Stent and Sequential Balloon Technique: A Better Strategy?

Clinically significant bifurcation lesions account for up to 20% of percutaneous coronary intervention (PCI) procedures, and present technical challenges due to the potential for occlusion of the side branch vessel. Percutaneous coronary intervention using final kissing ballooning (FKB) plays a major role in treating bifurcation lesions, but sequential dilatation (SD) is a less complicated PCI technique with a shallower learning curve. Previous studies have shown no benefit of FKB over SD, but wide-angle (>70°) bifurcation lesions may respond differently to narrow-angle bifurcation lesions. Retrospective analysis was carried out to compare outcomes of FKB and SD stenting specifically for wide-angle bifurcation lesions: 7,582 PCIs performed at a single medical centre between 1 January 2009 and 31 May 2016 were screened. This yielded 112 SD and 102 FKB cases for comparative analysis, which was conducted with respect to major adverse cardiac event (MACE)-free survival and target lesion revascularisation (TLR)-free survival rates. The comparative analysis was achieved using the log-rank test and presented as Kaplan-Meier curves. All baseline characteristics were balanced among the groups. The mean procedure and fluoroscopy times were significantly longer for patients with FKB than SD. Patients with SD had slightly better MACE and TLR rates than those with FKB in both the drug-eluting stent (DES) and bare metal stent (BMS) groups. In addition, patients with DES had slightly lower MACE and TLR rates than those with BMS in both the FKD and SD groups. Major adverse cardiac event-free survival and TLR-free survival rates were also slightly higher in patients with DES than those with BMS in both the FKD and SD groups. However, these differences were not statistically significant. These results suggest that the most applicable procedure for PCI of wide-angulated bifurcation stenosis would be a combination of DES and SD.

An execution control method for the Aerostack aerial robotics framework

Execution control is a critical task of robot architectures which has a deep impact on the quality of the final system. In this study, we describe a general method for execution control, which is a part of the Aerostack software framework for aerial robotics, and present technical challenges for execution control and design decisions to develop the method. The proposed method has an original design combining a distributed approach for execution control of behaviors (such as situation checking and performance monitoring) and centralizes coordination to ensure consistency of the concurrent execution. We conduct experiments to evaluate the method. The experimental results show that the method is general and usable with acceptable development efforts to efficiently work on different types of aerial missions. The method is supported by standards based on a robot operating system (ROS) contributing to its general use, and an open-source project is integrated in the Aerostack framework. Therefore, its technical details are fully accessible to developers and freely available to be used in the development of new aerial robotic systems.

Structural Studies of Macromolecules in Solution using Small Angle X-Ray Scattering

Protein-protein interactions involving proteins with multiple globular domains present technical challenges for determining how such complexes form and how the domains are oriented/positioned. Here, a protocol with the potential for elucidating which specific domains mediate interactions in multicomponent system through ab initio modeling is described. A method for calculating solution structures of macromolecules and their assemblies is provided that involves integrating data from small angle X-ray scattering (SAXS), chromatography, and atomic resolution structures together in a hybrid approach. A specific example is that of the complex of full-length nidogen-1, which assembles extracellular matrix proteins and forms an extended, curved nanostructure. One of its globular domains attaches to laminin γ-1, which structures the basement membrane. This provides a basis for determining accurate structures of flexible multidomain protein complexes and is enabled by synchrotron sources coupled with automation robotics and size exclusion chromatography systems. This combination allows rapid analysis in which multiple oligomeric states are separated just prior to SAXS data collection. The analysis yields information on the radius of gyration, particle dimension, molecular shape and interdomain pairing. The protocol for generating 3D models of complexes by fitting high-resolution structures of the component proteins is also given.

Structural Studies of Macromolecules in Solution using Small Angle X-Ray Scattering

Protein-protein interactions involving proteins with multiple globular domains present technical challenges for determining how such complexes form and how the domains are oriented/positioned. Here, a protocol with the potential for elucidating which specific domains mediate interactions in multicomponent system through ab initio modeling is described. A method for calculating solution structures of macromolecules and their assemblies is provided that involves integrating data from small angle X-ray scattering (SAXS), chromatography, and atomic resolution structures together in a hybrid approach. A specific example is that of the complex of full-length nidogen-1, which assembles extracellular matrix proteins and forms an extended, curved nanostructure. One of its globular domains attaches to laminin γ-1, which structures the basement membrane. This provides a basis for determining accurate structures of flexible multidomain protein complexes and is enabled by synchrotron sources coupled with automation robotics and size exclusion chromatography systems. This combination allows rapid analysis in which multiple oligomeric states are separated just prior to SAXS data collection. The analysis yields information on the radius of gyration, particle dimension, molecular shape and interdomain pairing. The protocol for generating 3D models of complexes by fitting high-resolution structures of the component proteins is also given.

Production of membrane proteins for characterisation of their pheromone-sensing and antimicrobial resistance functions

Despite the importance of membrane proteins in cellular processes, studies of these hydrophobic proteins present major technical challenges, including expression and purification for structural and biophysical studies. A modified strategy of that proposed previously by Saidijam et al. (2005) and others, for the routine expression of bacterial membrane proteins involved in environmental sensing and antimicrobial resistance (AMR), is proposed which results in purification of sufficient proteins for biophysical experiments. We report expression successes amongst a collection of enterococcal vancomycin resistance membrane proteins: VanTG, VanTG-M transporter domain, VanZ and the previously characterised VanS (A-type) histidine protein kinase (HPK). Using the same strategy, we report on the successful amplification and purification of intact BlpH and ComD2 HPKs of Streptococcus pneumoniae. Near-UV circular dichroism revealed both recombinant proteins bound their pheromone ligands BlpC and CSP2. Interestingly, CSP1 also interacted with ComD. Finally, we evaluate the alternative strategy for studying sensory HPKs involving isolated soluble sensory domain fragments, exemplified by successful production of VicKESD of Enterococcus faecalis VicK. Purified VicKESD possessed secondary structure post-purification. Thermal denaturation experiments using far-UV CD, a technique which can be revealing regarding ligand binding, revealed that: (a) VicKESD denaturation occurs between 15 and 50 °C; and (b) reducing conditions did not detectably affect denaturation profiles suggesting reducing conditions per se are not directly sensed by VicKESD. Our findings provide information on a modified strategy for the successful expression, production and/or storage of bacterial membrane HPKs, AMR proteins and sensory domains for their future crystallisation, and ligand binding studies.