Early career scientists converse on the future of soft robotics.

During the recent decade, we have witnessed an extraordinary flourishing of soft robotics. Rekindled interest in soft robots is partially associated with the advances in manufacturing techniques that enable the fabrication of sophisticated multi-material robotic bodies with dimensions ranging across multiple length scales. In recent manuscripts, a reader might find peculiar-looking soft robots capable of grasping, walking, or swimming. However, the growth in publication numbers does not always reflect the real progress in the field since many manuscripts employ very similar ideas and just tweak soft body geometries. Therefore, we unreservedly agree with the sentiment that future research must move beyond "soft for soft's sake." Soft robotics is an undoubtedly fascinating field, but it requires a critical assessment of the limitations and challenges, enabling us to spotlight the areas and directions where soft robots will have the best leverage over their traditional counterparts. In this perspective paper, we discuss the current state of robotic research related to such important aspects as energy autonomy, electronic-free logic, and sustainability. The goal is to critically look at perspectives of soft robotics from two opposite points of view provided by early career researchers and highlight the most promising future direction, that is, in our opinion, the employment of soft robotic technologies for soft bio-inspired artificial organs.

Novel Motion Sequences in Plant-Inspired Robotics: Combining Inspirations from Snap-Trapping in Two Plant Species into an Artificial Venus Flytrap Demonstrator.

The field of plant-inspired robotics is based on principles underlying the movements and attachment and adaptability strategies of plants, which together with their materials systems serve as concept generators. The transference of the functions and underlying structural principles of plants thus enables the development of novel life-like technical materials systems. For example, principles involved in the hinge-less movements of carnivorous snap-trap plants and climbing plants can be used in technical applications. A combination of the snap-trap motion of two plant species (Aldrovanda vesiculosa and Dionaea muscipula) has led to the creation of a novel motion sequence for plant-inspired robotics in an artificial Venus flytrap system, the Venus Flyflap. The novel motion pattern of Venus Flyflap lobes has been characterized by using four state-of-the-art actuation systems. A kinematic analysis of the individual phases of the new motion cycle has been performed by utilizing precise pneumatic actuation. Contactless magnetic actuation augments lobe motion into energy-efficient resonance-like oscillatory motion. The use of environmentally driven actuator materials has allowed autonomous motion generation via changes in environmental conditions. Measurement of the energy required for the differently actuated movements has shown that the Venus Flyflap is not only faster than the biological models in its closing movement, but also requires less energy in certain cases for the execution of this movement.

Tool changing 3D printer for rapid prototyping of advanced soft robotic elements.

In the field of soft robotics, pneumatic elements play an important role due to their sensitive and adaptive behavior. Nevertheless, the rapid prototyping of such actuators is still challenging since conventional 3D printers are not designed to fabricate airtight objects or to specify their bending behavior by combining materials of different stiffness. In order to address this challenge, a tool changing multi-material 3D printer has been constructed, which can be equipped with various print-heads fitted to the specific application. By alternately processing filaments with varying mechanical properties, a series of pneumatic elements was produced. The actuators were printed in thermoplastic polyurethane with shore hardness A70 for flexible parts and D65 for stiff parts. A novel procedure for the feature adaptation of the flow rate allowed the fabrication of vertically printed flexible membranes with a thickness of just 500µm. This way the bending and expanding printed structures can all be actuated with a pressure of 100 kPa or less. Furthermore, a new kind of generic actuator that is customizable to specific tasks and can perform complex motion behavior was designed. All together, these actuators demonstrate the high potential of the developed platform for further research on and production of soft robotic elements and complex pressurized systems.

Artificial Venus Flytraps: A Research Review and Outlook on Their Importance for Novel Bioinspired Materials Systems.

Bioinspired and biomimetic soft machines rely on functions and working principles that have been abstracted from biology but that have evolved over 3.5 billion years. So far, few examples from the huge pool of natural models have been examined and transferred to technical applications. Like living organisms, subsequent generations of soft machines will autonomously respond, sense, and adapt to the environment. Plants as concept generators remain relatively unexplored in biomimetic approaches to robotics and related technologies, despite being able to grow, and continuously adapt in response to environmental stimuli. In this research review, we highlight recent developments in plant-inspired soft machine systems based on movement principles. We focus on inspirations taken from fast active movements in the carnivorous Venus flytrap (Dionaea muscipula) and compare current developments in artificial Venus flytraps with their biological role model. The advantages and disadvantages of current systems are also analyzed and discussed, and a new state-of-the-art autonomous system is derived. Incorporation of the basic structural and functional principles of the Venus flytrap into novel autonomous applications in the field of robotics not only will inspire further plant-inspired biomimetic developments but might also advance contemporary plant-inspired robots, leading to fully autonomous systems utilizing bioinspired working concepts.

Adsorption and movement of water by skin of the Australian thorny devil (Agamidae: Moloch horridus).

Moisture-harvesting lizards, such as the Australian thorny devil Moloch horridus, have remarkable adaptations for inhabiting arid regions. Their microstructured skin surface, with channels in between overlapping scales, enables them to collect water by capillarity and passively transport it to the mouth for ingestion. We characterized this capillary water transport for live thorny devils using high-speed video analyses. Comparison with preserved specimens showed that live lizards are required for detailed studies of skin water transport. For thorny devils, there was no directionality in cutaneous water transport (unlike Phrynosoma) as 7 µl water droplets applied to the skin were transported radially over more than 9.2 mm. We calculated the total capillary volume as 5.76 µl cm-2 (dorsal) and 4.45 µl cm-2 (ventral), which is reduced to 50% filling by the time transportation ceases. Using micro-computed tomography and scanning electron microscopy of shed skin to investigate capillary morphology, we found that the channels are hierarchically structured as a large channel between the scales that is sub-divided by protrusions into smaller sub-capillaries. The large channel quickly absorbs water whereas the sub-capillary structure extends the transport distance by about 39% and potentially reduces the water volume required for drinking. An adapted dynamics function, which closely reflects the channel morphology, includes that ecological role.

Cutaneous water collection by a moisture-harvesting lizard, the thorny devil (Moloch horridus).

Moisture-harvesting lizards, such as the Australian thorny devil, Moloch horridus, have the remarkable ability to inhabit arid regions. Special skin structures, comprising a micro-structured surface with capillary channels in between imbricate overlapping scales, enable the lizard to collect water by capillarity and transport it to the mouth for ingestion. The ecological role of this mechanism is the acquisition of water from various possible sources such as rainfall, puddles, dew, condensation on the skin, or absorption from moist sand, and we evaluate here the potential of these various sources for water uptake by M. horridus The water volume required to fill the skin capillary system is 3.19% of body mass. Thorny devils standing in water can fill their capillary system and then drink from this water, at approximately 0.7 µl per jaw movement. Thorny devils standing on nearly saturated moist sand could only fill the capillary channels to 59% of their capacity, and did not drink. However, placing moist sand on skin replicas showed that the capillary channels could be filled from moist sand when assisted by gravity, suggesting that their field behaviour of shovelling moist sand onto the dorsal skin might fill the capillary channels and enable drinking. Condensation facilitated by thermal disequilibrium between a cool thorny devil and warm moist air provided skin capillary filling to approximately 0.22% of body weight, which was insufficient for drinking. Our results suggest that rain and moist sand seem to be ecologically likely water sources for M. horridus on a regular basis.

Traumatic asphyxia--fatal accident in an automatic revolving door.

Due to continuing modernisation, the number of automatic doors in routine use, including powered revolving doors, has increased in recent years. Automatic revolving doors are found mostly in department stores, airports, railway stations and hospitals. Although safety arrangements and guidelines concerning the installation of automatic doors are in existence, their disregard in conjunction with obsolete or incorrect installation can lead to fatal accidents. In this report, a 19-month-old boy is described whose right arm was caught between the elements of an automatic revolving door. As a direct result of rescue attempts, the child's body was drawn further into the narrow gap between elements of the door. To get the boy's body out of the 4-cm-wide gap between the fixed outer wall of the revolving door and the revolving inner, back-up batteries had to be disconnected so as to stop the electrical motor powering the door. Cardiopulmonary resuscitation was begun immediately after the rescue but was unsuccessful; the child was declared dead at the hospital he was taken to. The cause of death was a combination of compression-related skull and brain injury together with thoracic compression. This case shows an outstanding example of the preventive aspect as a special task of forensic medicine. Additionally, it serves as a warning for the correct installation and use of automatic revolving doors. Even so, small children should not use these doors on their own, but only with an alert companion, so as to prevent further fatal accidents of this sort.

Atlanto-axial rotatory subluxations in postmortem CT: radiologists be aware of a common pitfall.

The aim of the present study was to determine the frequency of atlanto-axial rotatory subluxations (AARS) in multi detector computed tomography (MDCT) performed on human corpses for forensic purposes and to investigate whether these are a physiological postmortem finding or indicate a trauma to the neck region. 80 forensic cases examined with MDCT from November 2003 to March 2007 were included in the study. The study was approved by the regional ethics committee. For each case volumes were rendered and investigated with reference to suspected AARS and any other anomalies of the head and neck region. The rotation of the head as well as in the atlanto-axial joint were measured and occurring AARS were judged according Fielding's classification. The finding of AARS was correlated to case criteria such as postmortem head rotation, sex, age, cause of death, time since death and further autopsy results. Statistical analysis was performed using Fisher's exact test, Wilcoxon's rank sums test and Chi-square test with Pearson approximation. 70% (n=56) of the cases included in the study presented with an AARS. A strong correlation (P<.0001) between suspected AARS and postmortem head rotation was found. Two cases presented with an atlanto-axial rotation greater than the head rotation. One showed an undiscovered lateral dislocation of the atlas, and one an unfused atlas-ring. There was no correlation to any further investigated case criteria. Ipsilateral AARS with head rotation alone does not indicate trauma to the neck. PmCT can substantially support forensic examinations of the skeleton, especially in body regions, which are elaborate to access at autopsy, such as the cervical spine. Isolated AARS (Fielding type I) on pmCT is usually a normal finding associated with ipsilateral head rotation.

[Cardiac rehabilitation in Germany: a successful model with promising prospects]. / Kardiologische Rehabilitation in Deutschland: Erfolgsmodell mit Perspektive.

Over the past 20 years the German Pension Insurance has rehabilitated nearly 800,000 patients with coronary heart disease. In particular, phase-II rehabilitation has been established as an integral part of cardiac patient care. However, the decreasing number of participants in phase-III must be seen critically. Today's cardiac rehabilitation is characterised by evidence-based treatment modules and a sophisticated quality assurance system that ensures quality orientation in all aspects, from access to rehabilitation through to aftercare. Future developments such as vocationally-oriented medical rehabilitation and the use of new technologies will further improve cardiac rehabilitation. Positive patient feedback and scientific evidence of the effectiveness of cardiac rehabilitation are further incentives to maintain this forward-looking approach.

Successful combined heart-bilateral lung-kidney transplantation from a same donor to treat severe hypertrophic cardiomyopathy with secondary pulmonary hypertension and renal failure: case report and review of the literature.

This study describes the first reported case of a combined heart-lung-kidney transplantation. Our patient suffered from hypertrophic cardiomyopathy due to long-standing hypertension with Dana Point Classification Group 2 pulmonary hypertension from the underlying cardiac disease, along with renal failure necessitating renal replacement therapy. Twenty months after the transplant procedure, she has stable pulmonary and renal function, plus has resumed a normal daily life with improving exercise tolerance. We propose that a combined heart-lung-kidney transplantation may be an acceptable therapeutic option for carefully selected patients with advanced, concomitant cardiac, pulmonary, and kidney disease.

Effect of VTE1 AND VTE4 gene inactivation on salt stress response in Arabidopsis thaliana.

The effect of inactivation of VTE1 and VTE4 genes, encoding enzymes involved in tocopherol biosynthesis, on concentrations of chlorophylls, carotenoids, anthocyanins and activity of catalase and guaiacol peroxidase in Arabidopsis thaliana under salt stress conditions were studied. It was shown, that the inactivation of the VTE4 gene in A. thaliana caused the decrease in concentrations of chlorophylls and carotenoids, and at the same time, inactivation of VTE1 gene resulted in 3.6-fold increase of catalase activity in comparison with the wild type. Under salt stress, the activities of guaiacol peroxidase increased in all investigated plant groups, while the concentrations of carotenoids increased only in the wild type and vte4 mutant line of A. thaliana. Salt stress did not change the concentrations of protein carbonyl groups and activities of catalase.

Feet rolled over by cars: radiological and histological considerations from experiments.

This study investigates the question of whether bone structures are injured when a vehicle rolls over a foot. A total of 15 detached feet from deceased persons who had donated their bodies to research were rolled over using a VW Passat station wagon. The feet were enclosed in various types of shoes. The front left tire of the vehicle, inflated to 1.8 bar and driven at walking speed, ran over the feet at a right angle to the long axis. The feet were dissected, and histological and radiological examinations were carried out. The only macroscopically well-defined abrasions of the epidermis were on the back of the foot in the area of contact with the tire and only where the foot had not been covered by a shoe. These abrasions were also well presented histologically. No injuries to the bone structures of the feet, in the form of incomplete fractures, corticalis interruptions or spongiosa compressions were ascertained, either radiologically or microradiologically.

The predicted probability of having positive non-sentinel lymph nodes in patients who received neoadjuvant chemotherapy for large operable breast cancer.

The accuracy of the nomogram in women with positive sentinel nodes following neoadjuvant chemotherapy (NCT) is unknown. The aim of this study was to evaluate the accuracy of the nomogram in patients receiving NCT. Between December 1999 and December 2005, we identified 233 patients who had a positive sentinel lymph node biopsy (SLNB) and complete axillary lymph node dissection at Magee-Womens Hospital of University of Pittsburgh Medical Center. Thirty-two patients (14%) had presented with clinically N0 breast cancer (BC) for which NCT was administered. The computerised BC nomogram was used to calculate the probability of non-sentinel node metastases utilising tumour size before NCT and after NCT for the same patient. The discrimination of the nomogram was assessed by calculating the area under (AUC) the receiver operating characteristic curve (ROC). The median patient age was 51.5 (range: 39-66) years in the NCT group of patients. Twelve patients (37%) had positive axillary non-sentinel lymph nodes (NSLNs). The nomogram was first validated in our institution for 201 patients without NCT and the predicted accuracy of the nomogram by the AUC was 0.73. The area under the ROC was identical regardless of whether pre- or posttreatment tumour size was used to determine predicted probability of NSLN metastases (0.66). The predictive accuracy of the nomogram was found to have less power for patients receiving NCT (0.66) than the non-NCT group of patients.

[Traumatic partial amputation of a penis--a reconstruction of the circumstances of the accident]. / Traumatische Teilamputation des Penis--zur Rekonstruktion eines Unfallgeschehens.

A 61-year-old man was admitted to hospital with a partially severed penis. The head of the penis (glans) had been completely severed, and the skin of the shaft and the corpora cavernosa had been ripped open. In the hospital the patient reported that his penis got caught in the hose attachment of an old Kobold vacuum cleaner that he was using to inflate an air mattress. He later made contradictory statements in his report to the insurance company, so we were asked to reconstruct the circumstances of the accident. The literature available to us only makes clinical observations about similar accidents, always with the assumption that the vacuum cleaner was used during masturbation or in order to achieve an erection. According to our reconstruction of the accident and an investigation of the vacuum cleaner attachment, however, we could not rule out the possibility of a household accident as described by the patient.

The effect of zolpidem on operant behavior and its relation to pharmacokinetics after intravenous and subcutaneous administration: concentration-effect relations.

We characterized the effects of i.v. and s.c. zolpidem (1-8 mg/kg) under a differential reinforcement of low-rate schedule (i.e. DRL 45 s) in 3-hour sessions. Both behavioral and pharmacokinetic-pharmacodynamic analyses were used with the intent to compare the effects of zolpidem with those of benzodiazepines reported previously under the same behavioral paradigm. Zolpidem increased the shorter-response [inter-response times (IRTs)<45 s] rate and decreased the reinforcement rate in a dose- and time-related fashion. The behavioral profiles of zolpidem were mainly similar to those of benzodiazepines, except zolpidem produced far fewer shorter IRT responses. Pharmacokinetically, zolpidem decays biexponentially with distributional and terminal elimination half-lives of 5.2 and 42 min, respectively. The absorption rate constant and absolute bioavailability for s.c. zolpidem were 0.083/min and of 84.1%, respectively. The pharmacodynamic parameters for the reinforcement rate, an index of timing performance, were determined by integration of behavioral and pharmacokinetic profiles in a between-subject design using the effect-linked inhibitory sigmoidal E(max) model. The pharmacokinetic-pharmacodynamic analysis revealed that the potency of zolpidem (concentration required to produce 50% maximal effects, IC(50)) in disrupting the timing performance was 0.129 microg/ml. The pharmacodynamic estimates of zolpidem were compared to our previous results for benzodiazepines.

Negligible tolerance produced by chronic intravenous alprazolam administration: a low serum drug concentration effect.

In 3-hr sessions, the authors investigated the onset, peak, and disappearance of the effects of alprazolam on performance under a differential reinforcement of low rate 45-s schedule in rats. Alprazolam was administered chronically as a daily bolus dose (2 mg/kg) via the intravenous route. Alprazolam decreased the reinforcement rate and increased the shorter response (nonreinforced) rate in a dose- and time-related fashion. Tolerance did not develop to the decreases in reinforcement rate; tolerance to increases in shorter response rate was negligible, occurring only at the low-concentration range. Clinically, an optimal dose regimen should be designed to avoid the tolerance development that occurs in the low serum benzodiazepine concentration range.

Spontaneous activity as a contingency-controlled behavior within an operant context: alprazolam concentration-effect relations after subcutaneous administration in rats.

RATIONALE: Environmental factors affect serum drug concentration-effect relations. For example, after midazolam administration, longer pre-session delays imposed in experimental chambers produced differential concentration-effect relations compared to those of shorter delays. OBJECTIVES: To evaluate the extent to which serum concentrations determine alprazolam's effects on spontaneous activity in the presence and absence of a differential reinforcement of low rate (DRL 45-s) contingency using pharmacokinetic-pharmacodynamic analysis. Serum concentrations reported here were simulated from our published pharmacokinetic parameters for alprazolam. METHODS: One group (n=8) was used to investigate alprazolam's effects on spontaneous activity within the DRL contingency by placing an activity platform beneath each operant chamber to monitor concurrently both spontaneous activity (large and small movements) and DRL performance (shorter-response and reinforcement rates) in 3-h sessions; a parallel group (n=7) was used without the operant context. The concentration-effect relation of the reinforcement rate was compared and contrasted with those of spontaneous activity. RESULTS: Alprazolam decreased large and small movements within the DRL contingency, which corresponded to that of reinforcement rates under the DRL 45-s schedule. In contrast, without the DRL contingency, alprazolam's effects on small movements were short-lived (i.e., 30 min) and no effects on large movements were detected. Hence, the predicted concentration-effect relations for the reinforcement rate function described those of spontaneous activity well within the operant context, but not those without the operant context. Furthermore, the latter showed no correlation between serum alprazolam concentration and large movements; a significant, but low negative correlation for small movements was observed. CONCLUSIONS: The duration of alprazolam's action was dependent on not only dose size but also the behavioral measure examined. By imposing the DRL contingency, spontaneous activity behaves as an ideal pharmacodynamic measure (i.e., continuous, sensitive, and objective).

Management strategies and financial performance in rural and urban hospitals.

This study identifies the difference in financial performance between rural and urban hospitals and examines whether or not that difference may be attributed to the emphasis of revenue enhancement over cost management strategies. Hospitals in Virginia were included in this study except for the two state university medical centers. Rural and urban hospitals were compared on 10 performance indicators grouped into four categories: revenues, costs, profits, and productivity. The results suggest that rural hospital profitability is dependent on cost management. Since rural hospitals achieved lower cost, better efficiency and productivity level than urban hospitals in Virginia, they demonstrate a significant higher level of profit.

Two procedures establishing preference for oral cocaine and lidocaine solutions which do not use an associative history with a reinforcer.

Groups of rats were exposed to daily, 3-h, fixed-time 1-min food-pellet delivery sessions, a procedure that produces overdrinking (schedule-induced polydipsia, SIP). Previous research demonstrated that rats drinking a drug or non-drug solution come to prefer that solution to water if the solution had (a) a past association with either a highly acceptable vehicle (e.g. glucose/saccharin), or (b) allowed rats to eschew drinking an unacceptable solution under SIP conditions. The present experiments show that under the solution-avoidance procedure, preference for a concurrent, alternative solution (0.19 mg/ml lidocaine or 0.24 mg/ml cocaine) occurred when a concentrated quinine solution alternative was either abruptly removed or faded. A concentrated cocaine solution, however, was minimally effective in producing a preference for 0.19 mg/ml lidocaine to water when cocaine concentration was faded. Flavor/nutrient-conditioning (conditioned reinforcement) and solution-eschewing (avoidance) procedures may throw light on the kinds of historical situations that determine the genesis of stable preferences for drugs and other substances.

Contribution of the active metabolite, norcocaine, to cocaine's effects after intravenous and oral administration in rats: pharmacodynamics.

RATIONALE: Oral cocaine is more effective than IV cocaine by pharmacokinetic and pharmacodynamic analysis. One explanation is involvement of the active metabolite, norcocaine, in cocaine's effects. OBJECTIVES: To evaluate norcocaine's contribution to oral cocaine's effects, norcocaine's effects as a parent compound were determined and compared to those of cocaine using a differential reinforcement of low rate (DRL 45-s) schedule and spontaneous activity (large and small movements) after IV and PO routes of administration. METHODS: The effects of cocaine and norcocaine on DRL performance (shorter-response and reinforcement rates) and spontaneous activity were investigated in 3-h sessions. The changes in effects across time (effect-time profiles) and dose-response curves (DRCs) were constructed to evaluate the duration of action and potency (ED50) of both drugs. RESULTS: Under the DRL 45-s schedule, effect-time profiles showed both drugs via the two routes of administration significantly increasing and decreasing shorter-response rates and reinforcement rates, respectively. However, cocaine produced greater effects on shorterresponse rates than norcocaine, while both drugs produced comparable effects on reinforcement rates. For spontaneous activity, although IV cocaine, PO cocaine, and PO norcocaine dose- and time-dependently increased spontaneous activity, cocaine's effects were more profound than those of norcocaine. Effect-time profiles revealed that the duration of drug action was a function of dose, route, and behavioral paradigm used. According to ED50 values, IV cocaine was more effective than PO cocaine; however, PO cocaine was more effective than IV cocaine as judged by ED50 values corrected for absolute oral bioavailability. CONCLUSIONS: Norcocaine's contribution to oral cocaine's effects on DRL performance is evident. Other mechanism(s), such as a greater acute tolerance to IV cocaine's effects than to PO cocaine's effects, can be excluded.