Field-mediated locomotor dynamics on highly deformable surfaces.

Studies of active matter-systems consisting of individuals or ensembles of internally driven and damped locomotors-are of interest to physicists studying nonequilibrium dynamics, biologists interested in individuals and swarm locomotion, and engineers designing robot controllers. While principles governing active systems on hard ground or within fluids are well studied, another class of systems exists at deformable interfaces. Such environments can display mixes of fluid-like and elastic features, leading to locomotor dynamics that are strongly influenced by the geometry of the surface, which, in itself, can be a dynamical entity. To gain insight into principles by which locomotors are influenced via a deformation field alone (and can influence other locomotors), we study robot locomotion on an elastic membrane, which we propose as a model of active systems on highly deformable interfaces. As our active agent, we use a differential driven wheeled robotic vehicle which drives straight on flat homogeneous surfaces, but reorients in response to environmental curvature. We monitor the curvature field-mediated dynamics of a single vehicle interacting with a fixed deformation as well as multiple vehicles interacting with each other via local deformations. Single vehicles display precessing orbits in centrally deformed environments, while multiple vehicles influence each other by local deformation fields. The active nature of the system facilitates a differential geometry-inspired mathematical mapping from the vehicle dynamics to those of test particles in a fictitious "spacetime," allowing further understanding of the dynamics and how to control agent interactions to facilitate or avoid multivehicle membrane-induced cohesion.

Robotic swimming in curved space via geometric phase.

Locomotion by shape changes or gas expulsion is assumed to require environmental interaction, due to conservation of momentum. However, as first noted in [J. Wisdom, Science 299, 1865-1869 (2003)] and later in [E. Guéron, Sci. Am. 301, 38-45 (2009)] and [J. Avron, O. Kenneth, New J. Phys, 8, 68 (2006)], the noncommutativity of translations permits translation without momentum exchange in either gravitationally curved spacetime or the curved surfaces encountered by locomotors in real-world environments. To realize this idea which remained unvalidated in experiments for almost 20 y, we show that a precision robophysical apparatus consisting of motors driven on curved tracks (and thereby confined to a spherical surface without a solid substrate) can self-propel without environmental momentum exchange. It produces shape changes comparable to the environment's inverse curvatures and generates movement of [Formula: see text] cm per gait. While this simple geometric effect predominates over short time, eventually the dissipative (frictional) and conservative forces, ubiquitous in real systems, couple to it to generate an emergent dynamics in which the swimming motion produces a force that is counter-balanced against residual gravitational forces. In this way, the robot both swims forward without momentum and becomes fixed in place with a finite momentum that can be released by ceasing the swimming motion. We envision that our work will be of use in a broad variety of contexts, such as active matter in curved space and robots navigating real-world environments with curved surfaces.

Collective dynamics in entangled worm and robot blobs.

Living systems at all scales aggregate in large numbers for a variety of functions including mating, predation, and survival. The majority of such systems consist of unconnected individuals that collectively flock, school, or swarm. However, some aggregations involve physically entangled individuals, which can confer emergent mechanofunctional material properties to the collective. Here, we study in laboratory experiments and rationalize in theoretical and robophysical models the dynamics of physically entangled and motile self-assemblies of 1-cm-long California blackworms (Lumbriculus variegatus, Annelida: Clitellata: Lumbriculidae). Thousands of individual worms form braids with their long, slender, and flexible bodies to make a three-dimensional, soft, and shape-shifting "blob." The blob behaves as a living material capable of mitigating damage and assault from environmental stresses through dynamic shape transformations, including minimizing surface area for survival against desiccation and enabling transport (negative thermotaxis) from hazardous environments (like heat). We specifically focus on the locomotion of the blob to understand how an amorphous entangled ball of worms can break symmetry to move across a substrate. We hypothesize that the collective blob displays rudimentary differentiation of function across itself, which when combined with entanglement dynamics facilitates directed persistent blob locomotion. To test this, we develop a robophysical model of the worm blobs, which displays emergent locomotion in the collective without sophisticated control or programming of any individual robot. The emergent dynamics of the living functional blob and robophysical model can inform the design of additional classes of adaptive mechanofunctional living materials and emergent robotics.

Mechanism and function of root circumnutation.

Early root growth is critical for plant establishment and survival. We have identified a molecular pathway required for helical root tip movement known as circumnutation. Here, we report a multiscale investigation of the regulation and function of this phenomenon. We identify key cell signaling events comprising interaction of the ethylene, cytokinin, and auxin hormone signaling pathways. We identify the gene Oryza sativa histidine kinase-1 (HK1) as well as the auxin influx carrier gene OsAUX1 as essential regulators of this process in rice. Robophysical modeling and growth challenge experiments indicate circumnutation is critical for seedling establishment in rocky soil, consistent with the long-standing hypothesis that root circumnutation facilitates growth past obstacles. Thus, the integration of robotics, physics, and biology has elucidated the functional importance of root circumnutation and uncovered the molecular mechanisms underlying its regulation.

Climate risk, culture and the Covid-19 mortality: A cross-country analysis.

Why have some countries done significantly better than others in fighting the Covid-19 pandemic? Had some countries been better prepared than others? This paper attempts to shed light on these questions by examining the role of climate risk and culture in explaining the cross-country variation in the Covid-19 mortality, while controlling for other potential drivers. In our analysis, we consider climate risk, readiness to climate change and individualism as main indicators reflecting the climate and culture status of individual countries. Using data from 110 countries, we find that the greater the climate risk; the lower the readiness to climate change and the more individualistic the society, the higher the pandemic mortality rate. We also present a series of sensitivity checks and show that our findings are robust to different specifications, alternative definitions of the mortality rate; and different estimation methods. One policy implication arising from our results is that countries that were better prepared for the climate emergency were also better placed to fight the pandemic. Overall, countries in which individuals look after each other and the environment, creating sustainable societies, are better able to cope with climate and public health emergencies.

The effect of cigarette smoking on the healing of extraction sockets: an immunohistochemical study.

The aim of this study was to investigate immunohistochemically the influence of cigarette smoking on the socket healing after tooth extraction in rats. Eighty-four male rats were divided into 3 groups; 2 groups were considered as experimental and the other as control. The animals in test 1 were exposed to smoking regimen before the surgery and after the surgery, but the animals in test 2 were exposed to the smoking regimen only before surgery. All animals' maxillary right central incisors were extracted and killed at the 3rd, 7th, 15th, and 28th day. The samples taken on third day after tooth extraction were stained immunohistochemically with fibronectin antibody and the other with type I collagen antibody. On the third day after tooth extraction, samples in the control group were intense stained (3) (+++); in the test 1 they were slight positive (1) (+) and in the test 2 they were moderate positive (2) (+ +). As a result of scoring type I collagen antibody, there was no statistically significant difference between the groups at seventh day, but there were statistically significant differences between the groups at the 15th and 28th day (P = 0.000 and P = 0.001, respectively). Comparison of the paired intense scores of type I collagen antibody staining according to days within each groups were not statistically significant. As a result, we have found out that the healing process of the tooth extraction socket is negatively affected by cigarette smoke.

Clinical and microbiological comparison of knotless/barbed and silk sutures for impacted third-molar surgery.

BACKGROUND: Several types of suture materials are available for oral surgery. However, the most used non-resorbable suture in oral surgery is 3/0 silk. The aim of the present study was to compare the effectiveness of knotless/barbed sutures with silk sutures during the postoperative period after the third molar surgery in terms of clinical and microbiological parameters. METHODS: The study comprised 38 patients who underwent surgical extraction of a mandibular impacted third molar. The patients were divided into two groups. The mucoperiosteal flap was closed using 3/0 knotless/barbed sutures for the test group and 3/0 silk sutures for the control group. The duration of suturing was recorded during surgery. Pain level, postoperative edema, and trismus were measured at 3 and 7 days after surgery. The status of plaque formation on the sutures was scored using the Plaque Index at 3 and 7 days after the surgery. At 7 days, the suture materials were removed and submitted to the laboratory for microbiological analysis. The level of pain during suture removal was also recorded by a Visual Analog Scale. RESULTS: The duration of suturing in the barbed sutures group was found significantly lower than in silk sutures (P<0.05). There was no significant difference between the suture types in terms of trismus and edema at 3 and 7 days after surgery (P>0.05). On the third day after surgery and during suture, removal pain scores were statistically significantly lower in the barbed suture group than in the silk suture group (P<0.05). The Plaque Index values of the barbed sutures were statistically significantly lower than that of the silk sutures at 3 and 7 days after surgery (P<0.05). Aerobic, anaerobic, and aerobic/anaerobic mean colony forming units (CFUs) were statistically significantly lower in the barbed suture group than in the silk suture group (P<0.05). CONCLUSIONS: Barbed sutures increase the ease of operation and patient comfort with less postoperative pain than silk sutures. Additionally, less plaque accumulation and lower bacterial colonization were found on the barbed/knotless sutures than on the silk sutures.

Evaluation of the effects of melatonin and vitamin D on wound healing in immunosuppressive rats following tooth extraction.

BACKGROUND: The aim of this study was to evaluate the effects of melatonin (MLT) and paricalcitol (PRC) on the healing of the extraction socket following tooth extraction in rats with cyclosporine-A (CsA). MATERIAL AND METHODS: 76 male Wistar rats were divided into five different groups, one of which was a control (C) group. All groups other than the control group were applied CsA (10 mg/kg/daily) intraperitoneally 7 days before the tooth extraction. The left upper incisors were extracted on day 8 and CsA injections were continued in all groups until sacrification. Starting from the day of tooth extraction, in group 1 (CsA) were given CsA, in group 2 (CsA+MLT) were applied intraperitoneal MLT injection in a dose of 4 mg/kg, in group 3 (CsA+PRC) were applied intraperitoneal PRC injection in a dose of 200 ng/kg, and in group 4 (CsA+MLT+PRC) were applied intraperitoneal PRC injection and intraperitoneal MLT until the day of sacrification of all groups. The subjects were sacrificed on day 7 and 14 following tooth extraction. For histopathological examination, the subjects stained Hemotoxylin-Eosin and evaluated histologically under the light microscope. The intensity of inflammation in extraction socket was scored based on a four-grade system. RESULTS: The level of inflammation was found to be lower in group C on day 7, while the inflammation value was found to be higher in the group 1 on day 14 (p>0.05). Statistically significant differences were found in the ossification values on day 7 between the groups(p<0.05). The percentage of ossification on day 7 was significantly lower in the group 1 than in the C and group 3, and significantly lower in the group 2 than in the group 3. The percentage of ossification on day 14 in the group 1 was significantly lower than in group C (p<0.05). CONCLUSIONS: CsA has a negative effect on bone healing. The application of MLT and PRC following the toxicity produced by CsA was found to positively affect the healing of the socket that develops after tooth extraction.

The effect of tail stiffness on a sprawling quadruped locomotion.

A distinctive feature of quadrupeds that is integral to their locomotion is the tail. Tails serve many purposes in biological systems, including propulsion, counterbalance, and stabilization while walking, running, climbing, or jumping. Similarly, tails in legged robots may augment the stability and maneuverability of legged robots by providing an additional point of contact with the ground. However, in the field of terrestrial bio-inspired legged robotics, the tail is often ignored because of the difficulties in design and control. In this study, we test the hypothesis that a variable stiffness robotic tail can improve the performance of a sprawling quadruped robot by enhancing its stability and maneuverability in various environments. In order to validate our hypothesis, we integrated a cable-driven, flexible tail with multiple segments into the underactuated sprawling quadruped robot, where a single servo motor working alongside a reel and cable mechanism regulates the tail's stiffness. Our results demonstrated that by controlling the stiffness of the tail, the stability of locomotion on rough terrain and the climbing ability of the robot are improved compared to the movement with a rigid tail and no tail. Our findings highlight that constant ground support provided by the flexible tail is key to maintaining stable locomotion. This ensured a predictable gait cycle, eliminating unexpected turning and slipping, resulting in an increase in locomotion speed and efficiency. Additionally, we observed the robot's enhanced climbing ability on surfaces inclined up to 20°. The flexibility of the tail enabled the robot to overcome obstacles without external sensing, exhibiting significant adaptability across various terrains.

Management of obstructive sleep apnea by maxillomandibular advancement surgery in an edentulous patient.

BACKGROUND: Maxillomandibular advancement (MMA) surgery is a surgical treatment option for treating the patients with obstructive sleep apnea (OSA). Surgical treatment of OSA by MMA surgery is a problem when it is encountered with an edentulous patient because of the intermaxillary fixation problem of the jaws. A paucity of information is available concerning MMA surgery for edentulous patients. MATERIALS AND METHODS: In this case report, we present the preoperative planning, orthognathic surgery, and postoperative phases of a 49-year-old edentulous severe OSA (apnea hypopnea index, 81.9 event/hr) patient who underwent MMA surgery. RESULTS: Polysomnographic examination 9 months after surgery revealed normalization of the somnographic evaluations (apnea hypopnea index, 1.3). CONCLUSIONS: The results reported in the present case showed that the surgical treatment of OSA by MMA surgery in edentulous patients could be successfully done. Further critical evaluations of this approach for the surgical treatment of edentulous OSA patients are needed.

Management of a laterally luxated upper incisor caused by the hit of a rifle stock.

Lateral luxation is the displacement of the tooth in a direction other than axial, which is accompanied by comminution or fracture of the alveolar socket. Lateral luxation is one of the most prevalent dental injuries among the general population, resulting in up to 27% of all dental wounds. All physical activities have an associated risk of orofacial injuries due to falls, collisions, and contact with hard surfaces. Just like any other training activities, military training exercises present a significant risk of dental traumas, which comprise 2% to 8% of all military dental emergencies. The aim of this report was to present a case of a dental lateral luxation caused by the hit of a rifle stock during close combat training. The tooth was extruded from its bony lock, temporarily filled with a calcium hydroxide-based paste, replaced into its original anatomic position, and secured with Ivy loop wirings. The permanent endodontic treatment was performed 4 weeks after repositioning. At the end of the 8-months follow-up, the tooth was asymptomatic and any pathological alterations were absent.

The impact of COVID-19 pandemic on patient satisfaction and clinical outcomes after treatment of odontogenic cysts with decompression followed by surgery.

OBJECTIVE: The global pandemic outbreak has caused significant limitations in the public's access to routine dental care. The aim of this study was to evaluate the patient satisfaction and clinical outcomes related to decompression treatment followed by surgery for large odontogenic cysts during COVID-19 pandemic. MATERIALS AND METHODS: The present study were performed in patients (n=11) with large odontogenic cysts treated at our institution between March 2020 to June 2021. Decompression was applied as a part of the conservative approach and followed by surgery. All surgical procedures were performed under local anesthesia. Patient satisfaction related to treatment was recorded via the Likert scale and Visual Analog Scale after the surgery. Gender, age, location of the lesion, histopathological features, pre-and post-decompression size of lesions, decompression time, reduction rate and patients satisfaction values were recorded. RESULTS: The mean age was 27 years and all patients were male. Mean follow-up time was on average 6.45 months. Histologic examination at the time of definitive surgery was 54.5% of the radicular cyst and 45.5% of odontogenic keratocyst. The mean reduction rate was 80.8%. No recurrence were recorded. Patient satisfaction values related to treatment modality were 3.91 for the Likert scale and 79.45% for the VAS scale. 81.8% of patients recommend this treatment modality for prospective patients. CONCLUSIONS: Results of this study supported that conservative management of large cystic lesions of jaws with decompression followed by surgery has favorable patient satisfaction scores and predictable to reduce the effects of radical surgery in COVID-19 pandemic.

Self-reconfigurable multilegged robot swarms collectively accomplish challenging terradynamic tasks.

Swarms of ground-based robots are presently limited to relatively simple environments, which we attribute in part to the lack of locomotor capabilities needed to traverse complex terrain. To advance the field of terradynamically capable swarming robotics, inspired by the capabilities of multilegged organisms, we hypothesize that legged robots consisting of reversibly chainable modular units with appropriate passive perturbation management mechanisms can perform diverse tasks in variable terrain without complex control and sensing. Here, we report a reconfigurable swarm of identical low-cost quadruped robots (with directionally flexible legs and tail) that can be linked on demand and autonomously. When tasks become terradynamically challenging for individuals to perform alone, the individuals suffer performance degradation. A systematic study of performance of linked units leads to new discoveries of the emergent obstacle navigation capabilities of multilegged robots. We also demonstrate the swarm capabilities through multirobot object transport. In summary, we argue that improvement capabilities of terrestrial swarms of robots can be achieved via the judicious interaction of relatively simple units.

Lateral bending and buckling aids biological and robotic earthworm anchoring and locomotion.

Earthworms (Lumbricus terrestris) are characterized by soft, highly flexible and extensible bodies, and are capable of locomoting in most terrestrial environments. Previous studies of earthworm movement focused on the use of retrograde peristaltic gaits in which controlled contraction of longitudinal and circular muscles results in waves of shortening/thickening and thinning/lengthening of the hydrostatic skeleton. These waves can propel the animal across ground as well as into soil. However, worms benefit from axial body bends during locomotion. Such lateral bending and buckling dynamics can aid locomotor function via hooking/anchoring (to provide propulsion), modify travel orientation (to avoid obstacles and generate turns) and even generate snake-like undulatory locomotion in environments where peristaltic locomotion results in poor performance. To the best of our knowledge, lateral bending and buckling of an earthworm's body has not yet been systematically investigated. In this study, we observed that within confined environments, worms use lateral bending and buckling to anchor their body to the walls of their burrows and tip (anterior end) bending to search the environment. This locomotion strategy improved the performance of our soft-bodied robophysical model of the earthworm both in a confined (in an acrylic tube) and above-ground heterogeneous environment (rigid pegs), where present peristaltic robots are relatively limited in terradynamic capabilities. In summary, lateral bending and buckling facilitates the mobility of earthworm locomotion in diverse terrain and can play an important role in the creation of low cost soft robotic devices capable of traversing a variety of environments.

Controlling subterranean forces enables a fast, steerable, burrowing soft robot.

Robotic navigation on land, through air, and in water is well researched; numerous robots have successfully demonstrated motion in these environments. However, one frontier for robotic locomotion remains largely unexplored-below ground. Subterranean navigation is simply hard to do, in part because the interaction forces of underground motion are higher than in air or water by orders of magnitude and because we lack for these interactions a robust fundamental physics understanding. We present and test three hypotheses, derived from biological observation and the physics of granular intrusion, and use the results to inform the design of our burrowing robot. These results reveal that (i) tip extension reduces total drag by an amount equal to the skin drag of the body, (ii) granular aeration via tip-based airflow reduces drag with a nonlinear dependence on depth and flow angle, and (iii) variation of the angle of the tip-based flow has a nonmonotonic effect on lift in granular media. Informed by these results, we realize a steerable, root-like soft robot that controls subterranean lift and drag forces to burrow faster than previous approaches by over an order of magnitude and does so through real sand. We also demonstrate that the robot can modulate its pullout force by an order of magnitude and control its direction of motion in both the horizontal and vertical planes to navigate around subterranean obstacles. Our results advance the understanding and capabilities of robotic subterranean locomotion.

Stretchable Nanocomposite Sensors, Nanomembrane Interconnectors, and Wireless Electronics toward Feedback-Loop Control of a Soft Earthworm Robot.

Sensors that can detect external stimuli and perceive the surrounding areas could offer an ability for soft biomimetic robots to use the sensory feedback for closed-loop control of locomotion. Although various types of biomimetic robots have been developed, few systems have included integrated stretchable sensors and interconnectors with miniaturized electronics. Here, we introduce a soft, stretchable nanocomposite system with built-in wireless electronics with an aim for feedback-loop motion control of a robotic earthworm. The nanostructured strain sensor, based on a carbon nanomaterial and a low-modulus silicone elastomer, allows for seamless integration with the body of the soft robot that can accommodate large strains caused by bending, stretching, and physical interactions with obstacles. A scalable, cost-effective, and screen-printing method manufactures an array of the strain sensors that are conductive and stretchable over 100% with a gauge factor over 38. An array of nanomembrane interconnectors enables a reliable connection between soft sensors and wireless electronics while tolerating the robot's multimodal movements. A set of computational and experimental studies of soft materials, stretchable mechanics, and hybrid packaging provides the key design factors for a reliable, nanocomposite sensor system. The miniaturized wireless circuit, embedded in the robot joint, offers real-time monitoring of strain changes during the motions of a robotic segment. Collectively, the soft sensor system presented in this work shows great potential to be integrated with other flexible, stretchable electronics for applications in soft robotics, wearable devices, and human-machine interfaces.

Effects of hyperbaric oxygen treatment on implant osseointegration in experimental diabetes mellitus.

OBJECTIVE: To evaluate whether hyperbaric oxygen (HBO) treatment has a favorable effect on implant osseointegration in diabetic rabbits. MATERIAL AND METHODS: An experimental diabetes model was induced in 32 New Zealand rabbits through IV injection of alloxan. After the state of diabetes had been confirmed, one dental implant was placed in the metaphysical region of each animal's tibia. After the implants' placements, the animals were divided into two groups. Half of the animals underwent HBO treatment, while the other group did not receive HBO treatment and served as the control group. The animals were euthanized at the 4th and 8th weeks. The osseointegration of the implants were compared by histomorphometry and resonance frequency analysis (RFA). RESULTS: The Bone Implant Contact (BIC) values were significantly higher in the HBO group than in the control group at the 4th week. There was no difference in the BIC values between the groups at the 8th week. There was no significant difference in the RFA scores between the groups both at the 4th and 8th weeks after the operation. CONCLUSION: Histomorphometry findings suggest that HBO has positive effect on implant osseointegration in the early healing period in diabetic rabbits. However, implant stability is not affected by HBO treatment.

Comparison of chemical composition of the essential oil of Laurus nobilis L. leaves and fruits from different regions of Hatay, Turkey.

The essential oils of the leaves and fruits from bay (Laurus nobilis L.) grown in Antakya, Yayladagi and Samandagi were isolated by solvent extraction and analysed by capillary gas chromatography (GC), gas chromatography and mass spectrometry (GC/MS). In Antakya, Yayladagi and Samandagi the chemical compositions of the fruits and leaves were similar according to qualitative and quantitative analysis. Although in both fruits and leaves the major component was found to be 1.8-Cineole a concentration of about 50% compared with essential oils. The composition of the essential oil from the leaves has high content of 1.8-Cineole, Sabinene and alpha-Terpinyl acetate, but a low content of a-Pinene, alpha-Phellandrene and trans-/beta-osimen. 1.8-Cineole was found major component of the leaves essential oil collected from Samandagi (59.94%) which is sea coast of region. Interestingly alpha-Pinene, beta-Pinene, alpha-Phellandrene, 1.8-Cineole and trans-beta-osimen were found the major components of fruits of Laurus nobilis L. harvested from Antakya, Yayladagi and Samandagi Trans-beta-osimen was detected as the major component of fruits essential oil collected again from Samandagi (28.35%)

Bilateral Double Maxillary Paramolars: A Rare Case Report.

Paramolars are rare supernumerary molars occurring buccally or lingually/palatally near the molar row. They may cause complications such as caries, periodontal disease and delay or prevention eruption of permanent teeth. Reports of bilateral entity are rarely found in the dental literature. The present article reports a rare case of bilateral double paramolars in the maxillary molar region in 21-year-old male patient.

Thymoma with immunodeficiency with multiple recurrent oral herpetic infections.

Thymomas with immunodeficiency (formerly Good's syndrome) are a rare acquired disease of combined T- and B-cell immunodeficiency accompanying a thymoma. Recurrent opportunistic infections associated with disorders of both humoral and cell-mediated immunity frequently accompany this rare primary, adult-onset immunodeficiency. This is a report of a case of a thymoma with immunodeficiency in a 65-year-old male patient who developed recurrent oral herpetic infections. He consulted us about recurrent vesiculo-ulcerative lesions on his tongue, lower lip, and buccal mucosa. Results of laboratory examinations indicated hypogammaglobulinemia accompanied by diminished B cells in the peripheral blood, which is consistent with the characteristic features of a thymoma with immunodeficiency. After a diagnosis confirming herpes simplex virus infection, systemic antiviral therapy was administered, which was effective for his vesiculo-ulcerative lesions at follow-up. When an intractable infection accompanied by a thymoma is encountered, increased awareness about the clinical and immunological profiles of this primary immunodeficiency may help in its early diagnosis, thereby preventing mortality.