A bio-hybrid odor-guided autonomous palm-sized air vehicle

Biohybrid systems integrate living materials with synthetic devices, exploiting their respective advantages to solve challenging engineering problems. One challenge of critical importance to society is detecting and localizing airborne volatile chemicals. Many flying animals depend their ability to detect and locate the source of aerial chemical plumes for finding mates and food sources. A robot with comparable capability could reduce human hazard and drastically improve performance on tasks such as locating disaster survivors, hazardous gas leaks, incipient fires, or explosives. Three advances are needed before they can rival their biological counterparts: (1) a chemical sensor with a much faster response time that nevertheless satisfies the size, weight, and power constraints of flight, (2) a design, sensor suite, and control system that allows it to move toward the source of a plume fully autonomously while navigating obstacles, and (3) the ability to detect the plume with high specificity and sensitivity among the assortment of chemicals that invariably exist in the air. Here we address the first two, introducing a human-safe palm-sized air vehicle equipped with the odor-sensing antenna of an insect, the first odor-sensing biohybrid robot system to fly. Using this sensor along with a suite of additional navigational sensors, as well as passive wind fins, our robot orients upwind and navigates autonomously toward the source of airborne plumes. Our robot is the first flying biohybrid system to successfully perform odor localization in a confined space, and it is able to do so while detecting and avoiding obstacles in its flight path. We show that insect antennae respond more quickly than metal oxide gas sensors, enabling odor localization at an improved speed over previous flying robots. By using the insect antennae, we anticipate a feasible path toward improved chemical specificity and sensitivity by leveraging recent advances in gene editing.

Immunophenotyping leukemias: the new force in hematology

OBJECTIVE

To review basic concepts of immunophenotyping leukemias and introduce clinical laboratory scientists (CLSs) to the technological changes utilized in this laboratory methodology.

DESIGN

Literature review.

DATA SYNTHESIS

Immunophenotyping in the clinical laboratory is emerging as an advantageous way to separate and classify leukemic malignancies. Immunophenotyping involves the use of flow cytometers and immunofluorescence in order to achieve great sensitivity and specificity for malignant cells. A basic understanding of components of the flow cytometer and how it works is necessary to understand immunophenotyping. Monoclonal antibodies specific to the malignant cells of question play an essential part in this technique. Various fluorescent dyes and cell panels also must be incorporated into the system. Analysis is done and statistics are plotted on dot plots that can be read by the CLS to give helpful insight into the etiology of disease process. Immunophenotyping is a very powerful tool that has the ability to revolutionize the clinical laboratory setting. The CLS working in hematology must become aware of and comfortable with this methodology.

Cost cutoff. Are you ready for Medicare's new PPS?

Medicare's new PPS will radically change the way skilled nursing facility managers think about acuity levels, therapies, and billing, among other key factors. How will it change the way you do your job, and what can you do to prepare for it?

Complete intraoperative small-bowel endoscopy in the evaluation of occult gastrointestinal bleeding using the sonde enteroscope

OBJECTIVE

To review our experience with intraoperative small-bowel Sonde enteroscopy in evaluating occult bleeding in the small intestine.

DESIGN

Retrospective study with 100% follow-up.

SETTING

University-affiliated, tertiary-care teaching hospital.

PATIENTS

Sixteen consecutive patients referred with occult gastrointestinal bleeding in whom esophagogastro-duodenoscopy , push enteroscopy, and colonoscopy had failed to identify the source of bleeding. Fourteen of the 16 patients had required one or more transfusions.

MAIN OUTCOME MEASURE

Completeness of visualization, diagnostic accuracy, and complications of the procedure and follow-up for recurrent bleeding.

RESULTS

In all 16 patients, intraoperative Sonde enteroscopy allowed visualization of the entire small bowel. In 14 of the 16, it revealed the cause of bleeding, which was ileal angiodysplasia in three patients, ileal ulcers in six patients, neoplasia in two patients, and ileal ulcers caused by Crohn's disease, small-intestinal enteropathy and varices caused by portal hypertension, and radiation stricture in one patient each. Two patients had normal small bowel mucosa. The patients with mucosal disease underwent small-bowel resection or oversewing of bleeding sites. Two surgical complications occurred: prolonged postoperative ileus (one patient) and small-bowel obstruction that resolved without surgery (one patient). Two of the patients with angiodysplasia had recurrent bleeding postoperatively.

CONCLUSIONS

Intraoperative Sonde enteroscopy is safe and effective in localizing small-intestinal bleeding sites, providing complete visualization of the small-bowel mucosa without enterotomy while avoiding the trauma that can be caused by push endoscopy. It is the diagnostic assessment of choice in selected patients with occult gastrointestinal bleeding of presumed small-bowel origin.

Massive primary lipoma of the scrotum

Most lipomas occurring in the scrotum originate and develop in the spermatic cord. In rare cases, however, lipomas originate in the fat cells of the subcutaneous tissues of the scrotal walls themselves. These primary lipomas of the scrotum vary in size. We describe a patient with a scrotal mass that, to our knowledge, is the largest scrotal lipoma originating in the tunica dartos reported in the English literature.

Adaptive hypertrophy of the digit following little finger to thumb transposition

This is a long-term retrospective study of eight patients who had undergone little finger to thumb transposition after traumatic thumb loss in order to evaluate the presence of long-term changes in the transposed digit. The transposed little finger, contralateral (nontransposed) little finger, and contralateral thumb were compared using standardized measurements of size, comparison photographs, x-rays, and volume determination using silicone mold impressions of these digits. Significant and marked hypertrophy of the transposed digit was demonstrated in all these patients. Comparison radiographs demonstrated that this enlargement was due to hypertrophy of both soft-tissue and osseous components. This study demonstrates that the little finger transposed to the thumb position undergoes an adaptive hypertrophy to become more thumblike in appearance as well as function.

Aggressive malignant hemangiopericytoma in the neck

Hemangiopericytomas are rare vascular tumors, one fourth of which occur in the head and neck. These lesions are characteristically slow growing and slow to metastasize. We describe an otherwise healthy patient with a hemangiopericytoma on the left side of his neck that metastasized to his chest wall within 3 months after the tumor was first observed. The metastasis occurred while the patient was receiving radiation therapy. The patient died soon afterward. This case illustrates the aggressive malignant potential of hemangiopericytomas.

Bacteriologic status of necrotic tissue in necrotizing pancreatitis

To confirm the accuracy of guided percutaneous aspiration (GPA) in distinguishing sterile from infected pancreatic necrosis, we have performed Brown-Brenn tissue Gram stains on pancreatic and peripancreatic necrotic tissue removed operatively in 15 patients. In eight patients judged to have sterile necrosis on the basis of negative cultures of pancreatic exudate obtained first preoperatively (by GPA) and then intraoperatively, necrotic tissue debrided at surgery was also free of bacteria. In seven patients judged to have infected necrosis on the basis of positive cultures of pancreatic exudate obtained first preoperatively (by GPA) and then intraoperatively, necrotic tissue debrided at surgery harbored a considerable number of bacteria. We conclude that GPA targeted to areas of necrosis accurately distinguishes infected necrosis from sterile necrosis, and in infected necrosis, the solid necrotic tissue as well as the fluid component contains bacteria. We therefore believe that infected necrosis is not likely to be eradicated by catheter drainage and should be treated by surgical debridement.

An in vitro method for screening for the presence of thepat-2 gene in tomatoes (Lycopersicon esculentum Mill.)

Under field conditions,pat-2, the gene which conditions parthenocarpy in tomatoes, is recessive. A simple method has been devised for distinguishing the heterozygote from the two homozygotes using tissue culture. Ovaries of plants segregating for thepat-2 gene were excised and cultured on a medium containing 100 ppm gibberellic acid. After three weeks in culture, three distinct ovary sizes could be seen. It was shown, using F 3 progeny tests, that the largest ovaries corresponded to those plants homozygous for thepat-2 gene, the smallest ovaries corresponded to those plants homozygous for the wild type allele, and the intermediate sized ovaries were the heterozygotes. The ability to identify the heterozygote would greatly simplify a backcross breeding program aimed at incorporating thepat-2 gene into commercial cultivars by eliminating the need for an F 3 progeny test to determine the genotype of a plant.

Adventitious shoot regeneration from leaf tissue of three pear (Pyrus sp.) cultivars in vitro

To develop an adventitious regeneration system for pear cultivars, several experiments were conducted with 2 cultivars of Pyrus communis L. ('Seckel' and 'Louise Bonne') and one cultivar of P. bretschneideri Rehd. ('Crystal Pear'). Half-leaves, taken from shoots proliferating on Lepoivre medium, were plated in petri-dishes on medium supplemented with various combinations of cytokinins and auxins. Cultures of the above cultivars had been established from mature trees. Among the growth regulators tested, thidiazuron (TDZ), combined with naphthalene-acetic acid (NAA), was the most efficient for stimulation of adventitious shoots. The optimum level of TDZ was about 3 uM; shoot regeneration was observed over a wide range of TDZ and NAA concentrations (0.5 to 5 uM and 2.5 to 13 um, respectively). Among different macronutrient compositions, 1/2 and 1/4 Murashige and Skoog were the most effective. Sucrose concentrations (10 to 50 g L-1) had a linear significant effect on shoot regeneration of 'Crystal Pear'.

Analyzing the effects of exogeneous polyamines and growth regulators on plating efficiency of sweet potato protoplasts using a central composite test design

The effects of exogenous polyamines and growth regulators on plating efficiency of greenhouse-grown sweet potato (Ipomoea batatas Lam.) petiole protoplasts after six days were analyzed using a central composite test design. The medium components screened were 1-naphthaleneacetic acid (NAA), 6-benzylaminopurine (BAP), putrescine (PUT), spermidine (SPD), and spermine (SPM), each at five concentrations. Stepwise multiple regression analysis revealed significant interaction of NAA with BAP, PUT, and SPD as reflected in plating efficiencies. The interactions of NAA with BAP, and with SPD, were positive. The interaction of NAA and PUT appeared complex. A slight negative interaction was detected between PUT and SPM. These results indicated that plating efficiency of sweet potato protoplasts is highly sensitive to the concentrations of the medium components tested and it should be possible to further optimize the plating medium. Among the media formulations tested, the highest plating efficiency (10.8% after 6 days) was observed with NAA at 4.5 uM, BAP at 1.5 uM, PUT at 35.0 uM, SPD at 5.0 uM, and SPM at 2.5 uM.