Feudalistic Platooning: Subdivide Platoons, Unite Networks, and Conquer Efficiency and Reliability.

Cooperative intelligent transportation systems (C-ITSs) such as platooning rely on a robust and timely network that may not always be available in sufficient quality. Out of the box hybrid networks only partly eliminate shortcomings: mutual interference avoidance, data load balancing, and data dissemination must be sophisticated. Lacking network quality may lead to safety bottlenecks that require that the distance between the following vehicles be increased. However, increasing gaps result in efficiency loss and additionally compromise safety as the platoon is split into smaller parts by traffic: maneuvers, e.g., cut-in maneuvers bear safety risks, and consequently lower efficiency even further. However, platoons, especially if they are very long, can negatively affect the flow of traffic. This mainly applies on entry or exit lanes, on narrow lanes, or in intersection areas: automated and non-automated vehicles in traffic do affect each other and are interdependent. To account for varying network quality and enable the coexistence of non-automated and platooned traffic, we present in this paper a new concept of platooning that unites ad hoc-in form of IEEE 802.11p-and cellular communication: feudalistic platooning. Platooned vehicles are divided into smaller groups, inseparable by surrounding traffic, and are assigned roles that determine the communication flow between vehicles, other groups and platoons, and infrastructure. Critical vehicle data are redundantly sent while the ad hoc network is only used for this purpose. The remaining data are sent-relying on cellular infrastructure once it is available-directly between vehicles with or without the use of network involvement for scheduling. The presented approach was tested in simulations using Omnet++ and Simulation of Urban Mobility (SUMO).

A Feasibility Study of a Traffic Supervision System Based on 5G Communication.

At present, autonomous driving vehicles are designed in an ego-vehicle manner. The vehicles gather information from their on-board sensors, build an environment model from it and plan their movement based on this model. Mobile network connections are used for non-mission-critical tasks and maintenance only. In this paper, we propose a connected autonomous driving system, where self-driving vehicles exchange data with a so-called road supervisor. All vehicles under supervision provide their current position, velocity and other valuable data. Using the received information, the supervisor provides a recommended trajectory for every vehicle, coordinated with all other vehicles. Since the supervisor has a much better overview of the situation on the road, more elaborate decisions, compared to each individual autonomous vehicle planning for itself, are possible. Experiments show that our approach works efficiently and safely when running our road supervisor on top of a popular traffic simulator. Furthermore, we show the feasibility of offloading the trajectory planning task into the network when using ultra-low-latency 5G networks.

Feasibility of precise and reliable glucose quantification in human whole blood samples by 1 tesla benchtop NMR.

The standard procedure for blood glucose measurements is enzymatic testing. This method is cheap, but requires small samples of open blood with direct contact to the test medium. In principle, NMR provides non-contact analysis of body fluids, but high-field spectrometers are expensive and cannot be easily utilized under clinical conditions. Low-field NMR systems with permanent magnets are becoming increasingly smaller and more affordable. The studies presented here aim at exploring the capabilities of low-field NMR for measuring glucose concentrations in whole blood. For this purpose, a modern 1 T benchtop NMR spectrometer was used. Challenges arise from broad spectral lines, the glucose peak locations close to the water signal, low SNR and the interference with signals from other blood components. Whole blood as a sample comprises even more boundary conditions: crucial for reliable results are avoiding the separation of plasma and cells by gravitation and reliable reference values. First, the accuracy of glucose levels measured by NMR was tested using aqueous glucose solutions and commercially available bovine plasma. Then, 117 blood samples from oral glucose tolerance testing were measured with minimal preparation by simple pulse-acquire NMR experiments. The analysis itself is the key to achieve high precision, so several approaches were investigated: peak integration, orthogonal projection to latent structure analysis and support vector machine regression. Correlations between results from the NMR spectra and the routine laboratory automated analyzer revealed an RMSE of 7.90 mg/dL for the best model. 91.5% of the model output lies within the limits of the German Medical Association guidelines, which require the glucose measurement to be within 11% of the reference method. It is concluded that spectral quantification of glucose in whole blood samples by high-quality NMR spectrometers operating at 1 T is feasible with sufficient accuracy.

Clinical hypothermia temperatures increase complement activation and cell destruction via the classical pathway.

BACKGROUND: Therapeutic hypothermia is a treatment modality that is increasingly used to improve clinical neurological outcomes for ischemia-reperfusion injury-mediated diseases. Antibody-initiated classical complement pathway activation has been shown to contribute to ischemia-reperfusion injury in multiple disease processes. However, how therapeutic hypothermia affects complement activation is unknown. Our goal was to measure the independent effect of temperature on complement activation, and more specifically, examine the relationship between clinical hypothermia temperatures (31-33°C), and complement activation. METHODS: Antibody-sensitized erythrocytes were used to assay complement activation at temperatures ranging from 0-41°C. Individual complement pathway components were assayed by ELISA, Western blot, and quantitative dot blot. Peptide Inhibitor of complement C1 (PIC1) was used to specifically inhibit activation of C1. RESULTS: Antibody-initiated complement activation resulting in eukaryotic cell lysis was increased by 2-fold at 31°C compared with 37°C. Antibody-initiated complement activation in human serum increased as temperature decreased from 37°C until dramatically decreasing at 13°C. Quantitation of individual complement components showed significantly increased activation of C4, C3, and C5 at clinical hypothermia temperatures. In contrast, C1s activation by heat-aggregated IgG decreased at therapeutic hypothermia temperatures consistent with decreased enzymatic activity at lower temperatures. However, C1q binding to antibody-coated erythrocytes increased at lower temperatures, suggesting that increased classical complement pathway activation is mediated by increased C1 binding at therapeutic hypothermia temperatures. PIC1 inhibited hypothermia-enhanced complement-mediated cell lysis at 31°C by up to 60% (P = 0.001) in a dose dependent manner. CONCLUSIONS: In summary, therapeutic hypothermia temperatures increased antibody-initiated complement activation and eukaryotic cell destruction suggesting that the benefits of therapeutic hypothermia may be mediated via other mechanisms. Antibody-initiated complement activation has been shown to contribute to ischemia-reperfusion injury in several animal models, suggesting that for diseases with this mechanism hypothermia-enhanced complement activation may partially attenuate the benefits of therapeutic hypothermia.

Management of Choledocholithiasis in a Community Hospital: Laparoscopic Common Bile Duct Exploration Versus Endoscopic Retrograde Cholangiopancreatography.

BACKGROUND: Approximately 10% of intraoperative cholangiograms identify choledocholithiasis (CDL), stones in the common bile duct. Choledocholithiasis management options include endoscopic retrograde cholangiopancreatography (ERCP) followed by cholecystectomy, laparoscopic cholecystectomy (LC) followed by ERCP (LC + ERCP), cholecystectomy with open common bile duct exploration, or laparoscopic cholecystectomy with laparoscopic common bile duct exploration (LC + LCBDE). The goal of these interventions is to clear the obstruction from CDL. METHODS: Patients from a single-center community hospital undergoing LC with intraoperative cholangiogram (LC + IOC) progressing to LC + LCBDE from July 2020 to August 2022 were evaluated for hospital length of stay (LOS), operative times, and complications. These were compared to the prior standard practice of pre/post-operative ERCP. RESULTS: The results were evaluated using ANOVA, Student-Newman-Keuls, and chi square analysis. In comparison of LC + CBDE to ERCP + cholecystectomy, LOS was reduced (1.8 vs 4.6 days P < .0001). No difference in LOS between LC + IOC and LC + CBDE (1.4 vs 1.8 days, P > .05) was found. No difference in complication rates was found. Mean operative time differed between LC + IOC and LC + CBDE (63 vs 113 minutes, P < .0001). Fifty-five attempts of LC + CBDE were performed with only 10 requiring post-operative ERCP. DISCUSSION: Since implementation of LC + CBDE, there has been reduced LOS without increasing complication rates. Operative times are increased with LC + CBDE but offset by reduced LOS, additional anesthesia events, and procedures. Our institution will continue to pursue LC + CBDE when indicated with efforts to improve resource allocation.

Formation of Biologic Plug and Patch Mesh for Use in Perforated Femoral Hernia.

Incarcerated inguinal hernias with contamination frequently lead to an open inguinal hernia primary repair. If no contamination is present, a tension-free repair with mesh is a good option. In this case, we encountered an incarcerated femoral hernia with perforation of the small bowel. We will describe and demonstrate via video how to incorporate a tension-free repair with mesh in a contaminated field with formation of a plug and patch made from biologic mesh.

Endoscopic Sleeve Gastroplasty Leading to Gastric Ischemia and Perforation.

Endoscopic sleeve gastroplasty (ESG) is performed by using endoscopic suctioning to reduce the volume of the stomach by plicating the greater curvature with an endoscopic suturing device or stapler. This allows for the endoscopist to perform an elective outpatient weight loss procedure. We will describe a single case of post-procedure day zero complication involving ESG resulting in ischemia, perforation, and peritonitis; what was discovered intra-operatively; and our operative management.

Incarcerated Amyand Hernia Associated With Acute Appendicitis and Incidental Finding of Serrated Adenoma.

BACKGROUND: Amyand hernias are rare as they represent 0.5% of all hernias. An Amyand hernia that is discovered due to acute appendicitis is even rarer, accounting for approximately 0.11% of cases. Furthermore, appendiceal neoplasms are infrequently encountered in only 0.7-1.7% of appendectomy specimens. PURPOSE: This paper presents the case of an 85 year-old man presenting with acute appendicitis located within an amyand hernia as well as a serrated adenoma noted on final pathology. CONCLUSIONS: An Amyand hernia is a rare diagnosis. We proceeded with laparoscopic appendectomy and interval inguinal hernia repair. Pathology should be reviewed for all patients and proper follow up ensured for all incidental findings.

Improving the Safety of Laparoscopic Cholecystectomy with Indocyanine Green Dye Using Critical View of Safety Plus.

BACKGROUND: During a laparoscopic cholecystectomy, the critical view of safety is obtained through dissection of the gallbladder from the liver until there is anterior and posterior visualization of the cystic duct and cystic artery. This view is used to allow for proper identification of the cystic duct and artery that will be clipped and incised during the operation. Indocyanine green (ICG) can be used during the operation to directly visualize the biliary tract because of its excretion through the biliary system and elimination via the GI tract. Using a laparoscope capable of visualizing ICG allows for identification of bile duct anatomy to include: common hepatic bile duct, cystic duct, and aberrant, or accessory bile ducts. Additionally, visualization of the biliary structures using ICG prior to clipping and incision will allow for identification and prevention of missed biliary anatomy which could reduce incidence of bile leak, a known complication of cholecystectomies. We propose that visualization of the critical view of safety with ICG fluoroscopy be termed the critical view of safety plus. PURPOSE: We hypothesized that using the critical view of safety plus method for laparoscopic cholecystectomy will yield better scores and increase the decision of the control surgeon to choose to cut and proceed with the operation when compared with the traditional critical view of safety. RESEARCH DESIGN: Comparision of operative photos of critical view of safety and critical view of safety plus which were randomized, double blinded, and graded by a single control surgeon. STUDY SAMPLE: Our study consisted of fifty patients of which 72% female (n = 36) and 28% male (n = 14). The ethnic background included 76% non-Hispanic (n = 38) and 24% Hispanic or of Latino/a origin (n = 12). The average age of our patient was 49 years old (range 20 to 93 years old). Inclusion criteria consisted of patients undergoing laparoscopic cholecystectomy greater than or equal to 18 years old. Exclusion criteria included allergy to indocyanine dye or iodine and pregnancy. ANALYSIS: The scores were evaluated using Chi-squared and paired T-test analysis using MedCalc, MedCalc Sofware Ltd, Belgium. RESULTS: The decision to cut and proceed with the operation was chosen 29 times (58%) when viewing the critical view of safety plus vs 22 times (44%) with the critical view of safety (χ2 = 65.822, p < 0.0001). The decision to proceed with further dissection to isolate the cystic duct viewing the critical view of safety plus was chosen 8 times (16%) vs 11 times (22%) with critical view of safety (χ2 = 65.822, p < 0.0001) as shown in Fig. 2. The comparison of total scores with critical view of safety plus vs critical view of safety showed an average of 4.36 vs 4.04, p = 0.0733. The critical view of safety plus and critical view of safety individual criteria scores are: "two structures connected to the gallbladder" (average 1.54 vs 1.50, p = 0.598), "cystic plate clearance" (average 1.42 vs 1.28, p = 0.018), and "hepatocystic triangle clearance" (average 1.4 vs 1.26, p =0.0334). CONCLUSION: We recommend routine use of ICG fluoroscopy to obtain the critical view of safety plus to allow for improved visualization of the biliary tree, identification of aberrant biliary anatomy, and the potential to reduce risk of bile duct injury.

Corrigendum: JTrack: A Digital Biomarker Platform for Remote Monitoring of Daily-Life Behaviour in Health and Disease.

[This corrects the article DOI: 10.3389/fpubh.2021.763621.].

The push-pull principle: an electrostatic actuator concept for low distortion acoustic transducers.

Electrostatic actuators are of particular interest for microsystems (MEMS), and in particular for MEMS audio transducers for use in advanced true wireless applications. They are attractive because of their typically low electrical capacitance and because they can be fabricated from materials that are compatible with standard complementary metal-oxide semiconductor (CMOS) technology. For high audio performance and in particular low harmonic distortion (THD) the implementation of the push-pull principle provides strong benefits. With an arrangement of three electrodes in a conjunct moving configuration on a beam, we demonstrate here for the first time a balanced bending actuator incarnating the push-pull principle operating at low voltages. Our first design already exhibits a harmonic distortion as low as 1.2% at 79 dB using a signal voltage of only 6 Vp and a constant voltage of only ±10 Vdc in a standard acoustic measurement setup. Thus, exceeding our previously reported approach in all three key performance indications at the same time. We expect that our novel electrode configurations will stimulate innovative electrostatic actuator developments for a broad range of applications. In this paper we report the basic theory, the fabrication and the performance of our novel actuator design acting as an audio transducer.

JTrack: A Digital Biomarker Platform for Remote Monitoring of Daily-Life Behaviour in Health and Disease.

Health-related data being collected by smartphones offer a promising complementary approach to in-clinic assessments. Despite recent contributions, the trade-off between privacy, optimization, stability and research-grade data quality is not well met by existing platforms. Here we introduce the JTrack platform as a secure, reliable and extendable open-source solution for remote monitoring in daily-life and digital-phenotyping. JTrack is an open-source (released under open-source Apache 2.0 licenses) platform for remote assessment of digital biomarkers (DB) in neurological, psychiatric and other indications. JTrack is developed and maintained to comply with security, privacy and the General Data Protection Regulation (GDPR) requirements. A wide range of anonymized measurements from motion-sensors, social and physical activities and geolocation information can be collected in either active or passive modes by using JTrack Android-based smartphone application. JTrack also provides an online study management dashboard to monitor data collection across studies. To facilitate scaling, reproducibility, data management and sharing we integrated DataLad as a data management infrastructure. Smartphone-based Digital Biomarker data may provide valuable insight into daily-life behaviour in health and disease. As illustrated using sample data, JTrack provides as an easy and reliable open-source solution for collection of such information.

Coulomb-actuated microbeams revisited: experimental and numerical modal decomposition of the saddle-node bifurcation.

Electrostatic micromechanical actuators have numerous applications in science and technology. In many applications, they are operated in a narrow frequency range close to resonance and at a drive voltage of low variation. Recently, new applications, such as microelectromechanical systems (MEMS) microspeakers (µSpeakers), have emerged that require operation over a wide frequency and dynamic range. Simulating the dynamic performance under such circumstances is still highly cumbersome. State-of-the-art finite element analysis struggles with pull-in instability and does not deliver the necessary information about unstable equilibrium states accordingly. Convincing lumped-parameter models amenable to direct physical interpretation are missing. This inhibits the indispensable in-depth analysis of the dynamic stability of such systems. In this paper, we take a major step towards mending the situation. By combining the finite element method (FEM) with an arc-length solver, we obtain the full bifurcation diagram for electrostatic actuators based on prismatic Euler-Bernoulli beams. A subsequent modal analysis then shows that within very narrow error margins, it is exclusively the lowest Euler-Bernoulli eigenmode that dominates the beam physics over the entire relevant drive voltage range. An experiment directly recording the deflection profile of a MEMS microbeam is performed and confirms the numerical findings with astonishing precision. This enables modeling the system using a single spatial degree of freedom.

Structural changes in the catalytic cycle of the Na+,K+-ATPase studied by infrared spectroscopy.

Pig kidney Na(+),K(+)-ATPase was studied by means of reaction-induced infrared difference spectroscopy. The reaction from E1Na(3)(+) to an E2P state was initiated by photolysis of P(3)-1-(2-nitrophenyl)ethyl ATP (NPE caged ATP) in samples that contained 3 mM free Mg(2+) and 130 mM NaCl at pH 7.5. Release of ATP from caged ATP produced highly detailed infrared difference spectra indicating structural changes of the Na(+),K(+)-ATPase. The observed transient state of the enzyme accumulated within seconds after ATP release and decayed on a timescale of minutes at 15 degrees C. Several controls ensured that the observed difference signals were due to structural changes of the Na(+),K(+)-ATPase. Samples that additionally contained 20 mM KCl showed similar spectra but less intense difference bands. The absorbance changes observed in the amide I region, reflecting conformational changes of the protein backbone, corresponded to only 0.3% of the maximum absorbance. Thus the net change of secondary structure was concluded to be very small, which is in line with movement of rigid protein segments during the catalytic cycle. Despite their small amplitude, the amide I signals unambiguously reveal the involvement of several secondary structure elements in the conformational change. Similarities and dissimilarities to corresponding spectra of the Ca(2+)-ATPase and H(+),K(+)-ATPase are discussed, and suggest characteristic bands for the E1 and E2 conformations at 1641 and 1661 cm(-1), respectively, for alphabeta heterodimeric ATPases. The spectra further indicate the participation of protonated carboxyl groups or lipid carbonyl groups in the reaction from E1Na(3)(+) to an E2P state. A negative band at 1730 cm(-1) is in line with the presence of a protonated Asp or Glu residue that coordinates Na(+) in E1Na(3)(+). Infrared signals were also detected in the absorption regions of ionized carboxyl groups.

The serine hydroxymethyltransferase gene glyA in Corynebacterium glutamicum is controlled by GlyR.

Serine hydroxymethyltransferase (SHMT) occupies a central position in one-carbon metabolism, and we here study its regulation in Corynebacterium glutamicum. Enzyme quantifications revealed an about 3-fold increase of SHMT activity during exponential growth with a further increase at the onset of the stationary phase. The SHMT encoding glyA gene was shown to be transcribed as a monocistronic mRNA, and its transcriptional start site was determined. Using DNA affinity chromatography the regulator GlyR (Cg0527) was identified and its chromosomal deletion shown to abolish the increase in SHMT activity in the stationary phase. The involvement of GlyR in glyA control was further confirmed by a transcriptional fusion of the glyA promoter with cat and chloramphenicol acetyltransferase quantifications. GlyR was isolated and mutational studies together with electrophoretic mobility shift assays showed that it binds to the imperfect palindromic motif CACT-N(2)-AATG in the -119 to -96 upstream region of the glyA promoter. These and further data illustrate that the essential SHMT has highest activity in the stationary phase and that GlyR acts as an activator of glyA transcription in this growth phase.

Concept and proof for an all-silicon MEMS micro speaker utilizing air chambers.

MEMS-based micro speakers are attractive candidates as sound transducers for smart devices, particularly wearables and hearables. For such devices, high sound pressure levels, low harmonic distortion and low power consumption are required for industrial, consumer and medical applications. The ability to integrate with microelectronic circuitry, as well as scalable batch production to enable low unit costs, are the key factors benchmarking a technology. The Nanoscopic Electrostatic Drive based, novel micro speaker concept presented in this work essentially comprises in-plane, electrostatic bending actuators, and uses the chip volume rather than the its surface for sound generation. We describe the principle, design, fabrication, and first characterization results. Various design options and governing equations are given and discussed. In a standard acoustical test setup (ear simulator), a MEMS micro speaker generated a sound pressure level of 69 dB at 500 Hz with a total harmonic distortion of 4.4%, thus proving the concept. Further potential on sound pressure as well as linearity improvement is outlined. We expect that the described methods can be used to enhance and design other MEMS devices and foster modeling and simulation approaches.

A small-gap electrostatic micro-actuator for large deflections.

Common quasi-static electrostatic micro actuators have significant limitations in deflection due to electrode separation and unstable drive regions. State-of-the-art electrostatic actuators achieve maximum deflections of approximately one third of the electrode separation. Large electrode separation and high driving voltages are normally required to achieve large actuator movements. Here we report on an electrostatic actuator class, fabricated in a CMOS-compatible process, which allows high deflections with small electrode separation. The concept presented makes the huge electrostatic forces within nanometre small electrode separation accessible for large deflections. Electrostatic actuations that are larger than the electrode separation were measured. An analytical theory is compared with measurement and simulation results and enables closer understanding of these actuators. The scaling behaviour discussed indicates significant future improvement on actuator deflection. The presented driving concept enables the investigation and development of novel micro systems with a high potential for improved device and system performance.

Reduced folate supply as a key to enhanced L-serine production by Corynebacterium glutamicum.

The amino acid L-serine is required for pharmaceutical purposes, and the availability of a sugar-based microbial process for its production is desirable. However, a number of intracellular utilization routes prevent overproduction of L-serine, with the essential serine hydroxymethyltransferase (SHMT) (glyA) probably occupying a key position. We found that constructs of Corynebacterium glutamicum strains where chromosomal glyA expression is dependent on Ptac and lacIQ are unstable, acquiring mutations in lacIQ, for instance. To overcome the inconvenient glyA expression control, we instead considered controlling SHMT activity by the availability of 5,6,7,8-tetrahydrofolate (THF). The pabAB and pabC genes of THF synthesis were identified and deleted in C. glutamicum, and the resulting strains were shown to require folate or 4-aminobenzoate for growth. Whereas the C. glutamicum DeltasdaA strain (pserACB) accumulates only traces of L-serine, with the C. glutamicum DeltapabABCDeltasdaA strain (pserACB), L-serine accumulation and growth responded in a dose-dependent manner to an external folate supply. At 0.1 mM folate, 81 mM L-serine accumulated. In a 20-liter controlled fed-batch culture, a 345 mM L-serine accumulation was achieved. Thus, an efficient and highly competitive process for microbial l-serine production is available.

Inhibition and partial reactions of Na,K-ATPase studied by Fourier transform infrared difference spectroscopy.

Reaction-induced infrared (IR) difference spectroscopy with caged ATP and Na,K-ATPase allows us to differentiate unambiguously between phosphorylated and unphosphorylated states of the enzyme as well as of its ouabain complex. The IR spectral changes upon phosphoenzyme formation are characterized and interpreted. Our results show clearly that high Na(+) concentrations prevent the binding of ouabain with high affinity, which is consistent with the results of a corresponding kinetic study employing spectrofluorimetry and calorimetric titrations. This unexpected antagonism leading to low ouabain affinity is assumed related to a conformation of the protein, induced by low affinity binding of the third Na(+) ion. We thus conclude that not the free enzyme but a phosphorylated state of the reaction cycle preferentially binds ouabain and leads to the loss of hydrolytic activity.

Removing coordinated metal ions from proteins: a fast and mild method in aqueous solution.

Thermodynamic and kinetic studies of metal binding to proteins require the investigation of metal-free proteins, which are often difficult to obtain. We have developed a very fast and mild method to eliminate metal ions from proteins by column chromatography using a commercially available Ni-NTA-type stationary phase. This material, initially designed for protein purification purposes in biotechnology, acts as a strong cation chelator when Ni2+ ions are removed. We have tested this new method with Ca-ATPase, an integral membrane protein exhibiting a strong affinity for Ca2+. By eluting the protein over the Ni2+-free NTA gel, we could remove 95% of the total Ca2+ and obtain an essentially Ca2+-free protein. This method is efficient with only a small amount of NTA gel, and we suggest that it can be applied in general for removal of metal ions from proteins. Moreover, as this procedure can be carried out under mild conditions, the chosen protein kept its enzymatic activity.