Sacrificial capillary pumps to engineer multiscalar biological forms.

Natural tissues are composed of diverse cells and extracellular materials whose arrangements across several length scales-from subcellular lengths (micrometre) to the organ scale (centimetre)-regulate biological functions. Tissue-fabrication methods have progressed to large constructs, for example, through stereolithography and nozzle-based bioprinting, and subcellular resolution through subtractive photoablation. However, additive bioprinting struggles with sub-nozzle/voxel features and photoablation is restricted to small volumes by prohibitive heat generation and time.

Now that the door is open: an update on ischemic stroke pharmacotherapeutics for the neurointerventionalist.

The last 10 years have seen a major shift in management of large vessel ischemic stroke with changes towards ever-expanding use of reperfusion therapies (intravenous thrombolysis and mechanical thrombectomy). These strategies 'open the door' to acute therapeutics for ischemic tissue, and we should investigate novel therapeutic approaches to enhance survival of recently reperfused brain. Key insights into new approaches have been provided through translational research models and preclinical paradigms, and through detailed research on ischemic mechanisms.

Engineering a living cardiac pump on a chip using high-precision fabrication.

Biomimetic on-chip tissue models serve as a powerful tool for studying human physiology and developing therapeutics; however, their modeling power is hindered by our inability to develop highly ordered functional structures in small length scales. Here, we demonstrate how high-precision fabrication can enable scaled-down modeling of organ-level cardiac mechanical function. We use two-photon direct laser writing (TPDLW) to fabricate a nanoscale-resolution metamaterial scaffold with fine-tuned mechanical properties to support the formation and cyclic contraction of a miniaturized, induced pluripotent stem cell-derived ventricular chamber.

Direct laser writing for cardiac tissue engineering: a microfluidic heart on a chip with integrated transducers.

We have developed a microfluidic platform for engineering cardiac microtissues in highly-controlled microenvironments. The platform is fabricated using direct laser writing (DLW) lithography and soft lithography, and contains four separate devices. Each individual device houses a cardiac microtissue and is equipped with an integrated strain actuator and a force sensor.

Controlled Cell Alignment Using Two-Photon Direct Laser Writing-Patterned Hydrogels in 2D and 3D.

Direct laser writing (DLW) via two-photon polymerization is an emerging highly precise technique for the fabrication of intricate cellular scaffolds. Despite recent progress in using two-photon-polymerized scaffolds to probe fundamental cell behaviors, new methods to direct and modulate microscale cell alignment and selective cell adhesion using two-photon-polymerized microstructures are of keen interest. Here, a DLW-fabricated 2D and 3D hydrogel microstructures, with alternating soft and stiff regions, for precisely controlled cell alignment are reported.

Fast micron-scale 3D printing with a resonant-scanning two-photon microscope.

3D printing allows rapid fabrication of complex objects from digital designs. One 3D-printing process, direct laser writing, polymerises a light-sensitive material by steering a focused laser beam through the shape of the object to be created. The highest-resolution direct laser writing systems use a femtosecond laser, steered using mechanised stages or galvanometer-controlled mirrors, to effect two-photon polymerisation.

Printable microscale interfaces for long-term peripheral nerve mapping and precision control.

The nascent field of bioelectronic medicine seeks to decode and modulate peripheral nervous system signals to obtain therapeutic control of targeted end organs and effectors. Current approaches rely heavily on electrode-based devices, but size scalability, material and microfabrication challenges, limited surgical accessibility, and the biomechanically dynamic implantation environment are significant impediments to developing and deploying peripheral interfacing technologies. Here, we present a microscale implantable device - the nanoclip - for chronic interfacing with fine peripheral nerves in small animal models that begins to meet these constraints.

From Simple to Architecturally Complex Hydrogel Scaffolds for Cell and Tissue Engineering Applications: Opportunities Presented by Two-Photon Polymerization.

Direct laser writing via two-photon polymerization (2PP) is an emerging micro- and nanofabrication technique to prepare predetermined and architecturally precise hydrogel scaffolds with high resolution and spatial complexity. As such, these scaffolds are increasingly being evaluated for cell and tissue engineering applications. This article first discusses the basic principles and photoresists employed in 2PP fabrication of hydrogels, followed by an in-depth introduction of various mechanical and biological characterization techniques used to assess the fabricated structures.

Synthesis of Functionalized Phenanthrenes via Regioselective Oxidative Radical Cyclization.

The majority of Sn-mediated cyclizations are reductive and, thus, cannot give a fully conjugated product. This is a limitation in the application of Sn-mediated radical cascades for the preparation of fully conjugated molecules. In this work, we report an oxidatively terminated Bu3Sn-mediated cyclization of an alkyne where AIBN, the commonly used initiator, takes on a new function as an oxidative agent.

The evolution of foot morphology in children between 6 and 17 years of age: a cross-sectional study based on footprints in a Mediterranean population.

Footprint evaluation is a widely used method for the determination of foot morphology, but its efficacy and validity are considered controversial. Dynamic footprints were obtained from both feet of 5,866 school-aged children (6-17 years old) to detect any foot changes during growth. The interpretation of the imprint was performed using a classification scheme consisting of 6 types of footprints.

Elastic properties of an intact and ACL-ruptured knee joint: measurement, mathematical modelling, and haptic rendering.

An analytical, dynamic model of the human knee joint has been developed to simulate the unloaded knee joint behaviour in 6 degrees of freedom. It is based on extensive robot-based measurements of the elastic properties of a human cadaver knee joint. The measured data are compared with data from the literature to ensure that a proper database for modelling is used.

Laparoscopic hernioplasty: why does it work?

Background: To understand how laparoscopic hernioplasty prevents early recurrence of hernia, we reviewed our first 1,000 patients. We analyzed the patients by age, sex, and hernia type and by whether their hernia was primary or recurrent.

Methods: The 1,000 patients had 1,336 hernias repaired by the transabdominal preperitoneal or the totally extraperitoneal approach.

Laparoscopic repair of recurrent hernia.

Background: Failure rates for recurrent hernioplasties vary from 3% to 30%. To help explain this high incidence of recurrence, we reviewed our 4-year experience using a laparoscopic approach and analyzed the characteristics of the recurrent hernias repaired.

Method: One hundred fifty-two patients with 173 recurrent hernias and 942 patients with 1,230 primary hernias were laparoscopically repaired using either a transabdominal preperitoneal or a totally extraperitoneal laparoscopic approach.

Direct right atrial catheter insertion with video-assisted thoracic surgery.

Chronic gastrointestinal disorders may require support with long-term total parenteral nutrition via a central venous catheter. Central venous access may be problematic because of infection or thrombosis of previous catheters. We report a case where video-assisted thoracic surgical catheter insertion directly into the right atrium provided a successful and safe method of long-term central venous access for parenteral nutrition.

Laparoscopic hernioplasty. TAPP vs TEP.

This study compares the results of two laparoscopic hernioplasties: the transabdominal preperitoneal (TAPP) and the totally extraperitoneal (TEP). Over a 43-month period 1,115 laparoscopic hernioplasties, 733 TAPP and 382 TEP, were performed in 866 patients. There were 11 major complications in the TAPP group (2 recurrences, 6 trocar hernias, 1 small-bowel obstruction, 1 trocar, and 1 dissection injury of the small bowel) compared to 1 recurrence and no intraperitoneal complications in the TEP group.

Laparoscopic repair of recurrent hernias.

The purpose of this study was to evaluate the results of a laparoscopic approach to recurrent inguinal hernia repair which dissected the entire inguinal floor and repaired all potential areas of recurrence without producing tension. Both a transabdominal preperitoneal and a totally extraperitoneal laparoscopic approach were utilized. Ninety recurrent hernias were repaired in 81 patients.

Open-mouth posture and maxillary arch width in young children: a three-year evaluation.

A large biracial sample of children were assessed for open mouth posture and maxillary arch width once a year for 3 years. Analyses revealed that although the youngsters exhibited open-mouth posture at high levels, over time, there was a significant decrease in this behavior. Racial and gender differences, as well as a race-by-time interaction, were also evidenced.

Laparoscopic repair of spigelian hernias.

Spigelian hernias can be difficult to diagnose and localize before surgical exploration. Four patients with abdominal wall hernias underwent laparoscopic diagnosis and repair of their spigelian hernias. The laparoscopic approach affords an accurate appraisal of the defect and a direct means of repair.

Laparoscopic repair of recurrent groin hernias.

Between November 1991 and May 1993, 54 recurrent groin hernias were laparoscopically repaired in 50 patients. Forty-eight were men and two were women. Forty-six recurrent hernias were unilateral and four bilateral.

Laparoscopic herniorrhaphy. Transabdominal preperitoneal floor repair.

The purpose of this study was to evaluate the results of a laparoscopic transabdominal preperitoneal (TAPP) approach to inguinal hernia repair which dissected the entire inguinal floor and repaired the indirect, direct, and femoral areas in all patients without tension. In our series, 183 patients had 205 hernia repairs and were followed for more than 6 months. Of this group, 128 hernias were indirect, 55 direct, 22 pantaloon, 26 recurrent, and 22 bilateral.

Open mouth posture and cross-sectional nasal area in young children.

A biracial sample of two-hundred ninety-six children were assessed for open-mouth posture (OMP) in the natural environment. In addition, rhinometry was performed on 288 of the youngsters. Means were computed for percent OMP and cross-sectional nasal airway.

Rhinometry and open-mouth posture in young children.

A biracial sample of 348 elementary school children who were in the first grade were assessed for open-mouth posture (OMP) in the natural environment. In addition, rhinometry was performed on 296 of the children. Means were computed for percent OMP and cross-sectional nasal airway.

Double-buttress laparoscopic herniorrhaphy.

To determine if laparoscopic inguinal herniorrhaphy can be performed safely in unselected patients, the authors' first 100 consecutive laparoscopic inguinal hernia repairs were reviewed. All patients with inguinal hernias who were candidates for general anesthetic were accepted for the study. Their ages ranged from 18 to 84 years.

A rare case of 'coccidioidoma' of the breast.

Coccidioidomycosis has been reported in almost every tissue of the human body. The gastrointestinal tract and breast have been uniquely spared from this fungal infection. Despite the exceedingly large number of screening mammographies that are performed every year, to our knowledge subcutaneous breast tissue involvement as the sole presentation or of secondary spread of coccidioidomycosis has not been reported.

Portal and peripheral vein concentrations of insulin and glucagon after arginine infusion in morbidly obese subjects.

Five morbidity obese subjects with fasting normoglycemia underwent catheterization of portal and peripheral veins immediately prior to jejunoileal bypass surgery. Levels of immunoreactive insulin (IRI), immunoreactive glucagon (IRG), and glucose were determined in simultaneously obtained serum samples before and after infusion of arginine. Portal levels exceeded peripheral levels by at least 50% with IRI and by 30%-40% with IRG.