Introducer-free MIS-assisted Ventriculoperitoneal Shunt Placement: A Technical Document

Background The placement of the distal catheter of a ventriculoperitoneal shunt (VPS) can be challenging in patients with a large body habitus. Given the complications associated with ventriculoperitoneal shunts and known infection risk of obese patients, new techniques for VPS placement that bypass the abdominal fat must be sought. By avoiding the abdominal fat, decreased complications and infection risk may be possible. Objective The objective of this technical document is to describe a laparoscopic approach to the abdominal cavity during ventriculoperitoneal shunt surgery that makes use of a direct tunneling technique into the peritoneal space. Methods We perform a ventriculoperitoneal shunt placement with distal catheter implantation under laparoscopic guidance. Tunneling of the distal abdominal catheter was done through the abdominal fascia directly, without creation of a stab incision for the insertion site. Intraoperative video media was obtained using video footage from OPTIVIEW camera. Results We have found this technique to be feasible and useful for patients with large body habitus. By eliminating the incision overlying the catheter there is decreased risk for infection by skin flora and overall decreased risk of complications. Conclusion Our technique of tunneling directly into the abdominal cavity is both novel and feasible. To our knowledge this is the first time this technique has been described. We believe that further study of this technique in a case series may highlight its advantages in a certain subpopulation of patients requiring VPS

Adding some Dirt to Clean energy: Applying clay nanocomposites in solar cells

Polymer clay nanocomposite (PCN) thin films have found application across a number of applications, ranging from oxygen barriers to flame retardants, where their resistance to molecular gas diffusion has proven remarkably effective, even in films only a few hundred nanometers thick. Deposited using a layer-by-layer processing approach that takes advantage of self-assembly of the constituent components, these composite thin films comprise highly organized, alternating molecular layers of functional polymers and exfoliated clay platelets, commonly montmorillonite or vermiculite. Here, we explore the potential application and utility of PCN thin films in solar cells, where they serve as conformal, transparent barrier films with the potential to impact solar cell lifetime, reliability, and safety. Solar cell failures commonly result when environmental moisture and corrosive or reactive gases penetrate a cell’s encapsulant. Moreover, such cell degradation can manifest as a gradual decline in solar cell performance or, in the case when degradation leads to significantly damaged electrical elements, much more dramatic arc-faults that can lead to complete and dramatic module failure, even igniting module fires. Here, we describe how the unique nanostructure, materials chemistry, and gas barrier properties of PCNs offer promise toward addressing these challenges. Applying the PCN coatings to various elements of a solar cell module, we demonstrate the efficacy of PCNs as gas barriers, corrosion inhibitors, and arc-fault flammability mitigators. I will discuss here not only the results of our studies but also potential mechanisms for effective PCN function and present some apparent limitations of select approaches to PCN integration. These results reveal significant potential for PCNs to impact photovoltaic and other energy-related technologies, and our work highlights how these diverse, highly functional thin films may offer tremendous new opportunities for other next generation materials advances. Please click Additional Files below to see the full abstract

End-Effector Contact and Force Detection for Miniature Autonomous Robots Performing Lunar and Expeditionary Surgery

Introduction: The U.S. Space Force was stood up on December 20, 2019 as an independent branch under the Air Force consisting of about 16,000 active duty and civilian personnel focused singularly on space. In addition to the Space Force, the plans by NASA and private industry for exploration-class long-duration missions to the moon, near-earth asteroids, and Mars makes semi-independent medical capability in space a priority. Current practice for space-based medicine is limited and relies on a “life-raft” scenario for emergencies. Discussions by working groups on military space-based medicine include placing a Role III equivalent facility in a lunar surface station. Surgical capability is a key requirement for that facility. Materials and Methods: To prepare for the eventuality of surgery in space, it is necessary to develop low-mass, low power, mini-surgical robots, which could serve as a celestial replacement for existing terrestrial robots. The current study focused on developing semi-autonomous capability in surgical robotics, specifically related to task automation. Two categories for end-effector tissue interaction were developed: Visual feedback from the robot to detect tissue contact, and motor current waveform measurements to detect contact force. Results: Using a pixel-to-pixel deep neural network to train, we were able to achieve an accuracy of nearly 90% for contact/nocontact detection. Large torques were predicted well by a trained long short-term memory recursive network, but the technique did not predict small torques well. Conclusion: Surgical capability on long-duration missions will require human/machine teaming with semi-autonomous surgical robots. Our existing small, lightweight, low-power miniature robots perform multiple essential tasks in one design including hemostasis, fluid management, suturing for traumatic wounds, and are fully insertable for internal surgical procedures. To prepare for the inevitable eventuality of an emergency surgery in space, it is essential that automated surgical robot capabilities be developed

Freshwater ecoregions of the world: A new map of biogeographic units for freshwater biodiversity conservation

We present a new map depicting the first global biogeographic regionalization of Earth's freshwater systems. This map of freshwater ecoregions is based on the distributions and compositions of freshwater fish species and incorporates major ecological and evolutionary patterns. Covering virtually all freshwater habitats on Earth, this ecoregion map, together with associated species data, is a useful tool for underpinning global and regional conservation planning efforts (particularly to identify outstanding and imperiled freshwater systems); for serving as a logical framework for large-scale conservation strategies; and for providing a global-scale knowledge base for increasing freshwater biogeographic literacy. Preliminary data for fish species compiled by ecoregion reveal some previously unrecognized areas of high biodiversity, highlighting the benefit of looking at the world's freshwaters through a new framework.La lista completa de autores que integran el documento puede consultarse en el archivo.Facultad de Ciencias Naturales y Muse

Freshwater ecoregions of the world: A new map of biogeographic units for freshwater biodiversity conservation

We present a new map depicting the first global biogeographic regionalization of Earth's freshwater systems. This map of freshwater ecoregions is based on the distributions and compositions of freshwater fish species and incorporates major ecological and evolutionary patterns. Covering virtually all freshwater habitats on Earth, this ecoregion map, together with associated species data, is a useful tool for underpinning global and regional conservation planning efforts (particularly to identify outstanding and imperiled freshwater systems); for serving as a logical framework for large-scale conservation strategies; and for providing a global-scale knowledge base for increasing freshwater biogeographic literacy. Preliminary data for fish species compiled by ecoregion reveal some previously unrecognized areas of high biodiversity, highlighting the benefit of looking at the world's freshwaters through a new framework.La lista completa de autores que integran el documento puede consultarse en el archivo.Facultad de Ciencias Naturales y Muse

Freshwater ecoregions of the world: A new map of biogeographic units for freshwater biodiversity conservation

We present a new map depicting the first global biogeographic regionalization of Earth's freshwater systems. This map of freshwater ecoregions is based on the distributions and compositions of freshwater fish species and incorporates major ecological and evolutionary patterns. Covering virtually all freshwater habitats on Earth, this ecoregion map, together with associated species data, is a useful tool for underpinning global and regional conservation planning efforts (particularly to identify outstanding and imperiled freshwater systems); for serving as a logical framework for large-scale conservation strategies; and for providing a global-scale knowledge base for increasing freshwater biogeographic literacy. Preliminary data for fish species compiled by ecoregion reveal some previously unrecognized areas of high biodiversity, highlighting the benefit of looking at the world's freshwaters through a new framework.La lista completa de autores que integran el documento puede consultarse en el archivo.Facultad de Ciencias Naturales y Muse

Detecting forest degradation patterns in Southeast Cameroon

The objective of this study was to evaluate the use of a spectral index and a contextual classifier for detection of forest degradation associated to selective logging in Southern Cameroon. This methodology, already applied in the Amazon, builds the Normalized Difference Fraction Index (NDFI) to enhance the forest canopy damage signal. A contextual classification algorithm (CCA) applied later to the NDFI image enables the separation of anthropogenic disturbance. These methods were tested in a certified forest concession area of Southern Cameroon, in the Congo Basin. The results show that the NDFI is able to detect infrastructure associated to most selective logging operations in the study area. The additional CCA was able to accurately discriminate human-caused forest degradation from natural occurrences.Pages: 1606-161

Seismic hazard in the Sea of Marmara following the Izmit Earthquake

On 17 August 1999, a destructive magnitude 7.4 earthquake occurred 100 km east of Istanbul, near the city of Izmit, on the North Anatolian fault. This 1,600-km-long plate boundary1,2 slips at an average rate of 2–3 cm yr−1 (refs 3–5), and historically has been the site of many devastating earthquakes6,7. This century alone it has ruptured over 900 km of its length6. Models of earthquake-induced stress change8 combined with active fault maps9 had been used to forecast that the epicentral area of the 1999 Izmit event was indeed a likely location for the occurrence of a large earthquake9,10. Here we show that the 1999 event itself significantly modifies the stress distribution resulting from pre- vious fault interactions9,10. Our new stress models take into account all events in the region with magnitudes greater than 6 having occurred since 1700 (ref. 7) as well as secular interseismic stress change, constrained by GPS data11. These models provide a consistent picture of the long term spatio–temporal behaviour of the North Anatolian fault and indicate that two events of magnitude equal to, or greater than, the Izmit earthquake are likely to occur within the next decades beneath the Marmara Sea, south of Istanbul

Mesoporous silica-supported lipid bilayers (protocells) for DNA cargo delivery to the spinal cord

AbstractAmorphous mesoporous silica nanoparticles (‘protocells’) that support surface lipid bilayers recently characterized in vitro as carrier constructs for small drug and DNA delivery are reported here as highly biocompatible both in vitro and in vivo, involving the brain and spinal cord following spinal delivery into the lumbosacral subarachnoid space (intrathecal; i.t.). Specifically, positively charged, 1, 2-Dioleoyl-3-Trimethylammonium-Propane (DOTAP)–cholesterol (DOTAP:Chol) liposome-formulated protocells revealed stable in vitro cargo release kinetics and cellular interleukin-10 (IL-10) transgene transfection. Recent approaches using synthetic non-viral vector platforms to deliver the pain-suppressive therapeutic transgene, IL-10, to the spinal subarachnoid space have yielded promising results in animal models of peripheral neuropathy, a condition involving aberrant neuronal communication within sensory pathways in the nervous system.Non-viral drug and gene delivery protocell platforms offer potential flexibility because cargo release-rates can be pH-dependent. We report here that i.t. delivery of protocells, with modified chemistry supporting a surface coating of DOTAP:Chol liposomes and containing the IL-10 transgene, results in functional suppression of pain-related behavior in rats for extended periods. This study is the first demonstration that protocell vectors offer amenable and enduring in vivo biological characteristics that can be applied to spinal gene delivery