CANDYBOTS: A New Generation of 3D-Printed Sugar-Based Transient Small-Scale Robots.

Sugars are ubiquitous in food, and are among the main sources of energy for almost all forms of life. Sugars can also form structural building blocks such as cellulose in plants. Because of their inherent degradability and biocompatibility characteristics, sugars are compelling materials for transient devices. Here, an additive manufacturing approach for the production of magnetic sugar-based composites is introduced. First, it is shown that sugar-based 3D architectures can be 3D printed by selective laser sintering. This method enables not only the caramelization chemistry but also the mechanical properties of the sugar architectures to be adjusted by varying the laser energy. It is also demonstrated that mixtures of sugar and magnetic particles can be processed as 3D composites. As a proof of concept, a sugar-based millimeter-scale helical swimmer, which is capable of corkscrew motion in a solution with a viscosity comparable to those of biological fluids, is fabricated. The millirobot quickly dissolves in water, while being manipulated through magnetic fields. The present fabrication method can pave the way to a new generation of transient sugar-based small-scale robots for minimally invasive procedures. Due to their rapid dissolution, sugars can be used as an intermediate step for transporting swarms of particles to specific target locations.

Studies of miscibility and specific interactions of antitumor-active anhydride copolymer and poly(ethylene glycol) blends.

The blending of polymers is of great interest, since the modification gives rise to diverse physical properties with the functionality of a polymer, without synthesis. Water-soluble antitumor-active poly(maleic anhydride-alt-acrylic acid) poly(MA-alt-AA) and poly(ethylene glycol) (PEG) blends were prepared by casting, and compatible properties were investigated by dilute solution viscometry. Viscosity measurements were made on ternary systems of polymer (1)/polymer (2)/solvent (H2O) and p-dioxane, at different concentrations of PEG and poly(MA-alt-AA). The interaction parameters Δß, µ, Δk, Δb, ß and α, which have been proposed, have been obtained using the viscosity data, to probe the miscibility of the polymer blends. The solid blends prepared were characterized with ATR-FTIR, (1)H-NMR, DTA and TGA.

Molecular phenotypic profiling of a Saccharomyces cerevisiae strain at the single-cell level.

Studying cell-to-cell heterogeneity requires techniques which robustly deliver reproducible results with single-cell sensitivity. Through a new fabrication method for the microarrays for mass spectrometry (MAMS) platform, we now have attained robustness and reproducibility in our single-cell level mass spectrometry measurements that allowed us to combine single-cell MAMS-based measurements from different days and samples. By combining multiple measurements, we were able to identify three co-existing phenotypes in an isogenic population of Saccharomyces cerevisiae characterized by distinctively different levels of glycolytic intermediates.

Superparamagnetic microrobots: fabrication by two-photon polymerization and biocompatibility.

This work presents the fabrication and controlled actuation of swimming microrobots made of a magnetic polymer composite (MPC) consisting of 11-nm-diameter magnetite (Fe3O4) nanoparticles and photocurable resin (SU-8). Two-photon polymerization (TPP) is used to fabricate the magnetic microstructures. The material properties and the cytotoxicity of the MPC with different nanoparticle concentrations are characterized. The live/dead staining tests indicate that MPC samples with varied concentrations, up to 10 vol.%, have negligible cytotoxicity after 24 h incubation. Fabrication parameters of MPC with up to 4 vol.% were investigated. We demonstrate that the helical microdevices made of 2 vol.% MPC were capable of performing corkscrew motion in water applying weak uniform rotating magnetic fields.

Dermatoscopy of flat pigmented facial lesions: diagnostic challenge between pigmented actinic keratosis and lentigo maligna.

BACKGROUND: The similarity between clinical pictures of pigmented actinic keratosis (PAK) and lentigo maligna (LM) is well known. OBJECTIVES: To investigate the frequency of dermatoscopic findings suggestive of LM/lentigo maligna melanoma (LMM) in the other facial pigmented skin lesions (FPSL) and to assess the distinguishing dermoscopic criteria of PAK and LM. METHODS: Eighty-nine FPSL were evaluated with conventional dermatoscopy. The lesions showing one or more dermatoscopic features considered as specific patterns for the diagnosis of LM/LMM, mainly slate-grey to black dots and globules, slate-grey areas, annular-granular pattern, asymmetrical pigmented follicular openings, black blotches, rhomboidal structures, hyperpigmented rim of follicular openings, slate-grey streaks and dark streaks, were included in the study selectively. RESULTS: PAK was diagnosed in 67, LM or LMM in 20 and lichen planus-like keratosis in two lesions, histopathologically. Eleven essential dermatoscopic features were observed in facial PAK: slate-grey dots (70%); annular-granular pattern (39%); rhomboidal structures (36%); pseudonetwork (36%); black globules (34%); slate-grey globules (33%); black dots (30%); asymmetrical pigmented follicular openings (25%); hyperpigmented rim of follicular openings (21%); slate-grey areas (18%); and streaks (3%). CONCLUSIONS: PAK has a striking similarity to LM/LMM in clinical and dermatoscopic features, thus representing a diagnostic challange. All dermatoscopic findings except black blotches were observed in PAK. As dermatoscopic diagnosis of a pigmented skin lesion cannot be based on the presence of a single criterion, we may conclude that histopathology still remains the gold standard for correct diagnosis.

MR imaging features of foot involvement in patients with psoriasis.

OBJECTIVE: To determine alterations of the soft tissues, tendons, cartilage, joint spaces, and bones of the foot using magnetic resonance (MR) imaging in patients with psoriasis. MATERIALS AND METHODS: Clinical and MR examination of the foot was performed in 26 consecutive patients (52 ft) with psoriasis. As a control group, 10 healthy volunteers (20 ft) were also studied. Joint effusion/synovitis, retrocalcaneal bursitis, retroachilles bursitis, Achilles tendonitis, soft-tissue edema, para-articular enthesophytes, bone marrow edema, sinus tarsi syndrome, enthesopathy at the Achilles attachment and at the plantar fascia attachment, plantar fasciitis, tenosynovitis, subchondral cysts, and bone erosions, joint space narrowing, subchondral signal changes, osteolysis, luxation, and sub-luxation were examined. RESULTS: Clinical signs and symptoms (pain and swelling) due to foot involvement were present in none of the patients while frequency of involvement was 92% (24/26) by MR imaging. The most common MR imaging findings were Achilles tendonitis (acute and peritendinitis) (57%), retrocalcaneal bursitis (50%), joint effusion/synovitis (46%), soft-tissue edema (46%), and para-articular enthesophytes (38%). The most commonly involved anatomical region was the hindfoot (73%). CONCLUSION: Our data showed that the incidence of foot involvement was very high in asymptomatic patients with psoriasis on MR imaging. Further MR studies are needed to confirm these data. We conclude that MR imaging may be of importance especially in early diagnosis and treatment of inflammatory changes in the foot.

Robotic assisted thoracic surgery for resection of an esophageal cyst.

Many centers around the world are now developing robotic surgical programs. The benefit of robotics, particularly in those centers where there is already expertise with minimally invasive surgical techniques, is unclear. We present the case of a 58-year-old man presenting with an esophageal cyst. This was removed using a robotic assisted, VATS (video assisted thoracic surgery) approach. The technical details of the procedure are described. Additionally, a discussion of the relative merits of using a robotic rather than a standard minimally invasive approach is discussed. In a procedure such as the case described, the critical parts of the procedure are focused within a small operative field. We believe that the articulating instrumentation and the 3-dimensional magnified view provided by the robot offers significant advantages over a standard VATS approach.

Enhancement kinetics of normal ovaries on dynamic contrast-enhanced MR imaging.

OBJECTIVE: The objective was to determine the enhancement kinetics of the normal ovaries in healthy women on dynamic contrast-enhanced magnetic resonance (DCE-MR) imaging. METHOD: Twenty-one women who had normal ovulatory cycles (volunteers; mean age=26.3 years, range=20-35), normal hormone profile, and apparently normal ovaries on ultrasonographic scan underwent DCE-MR imaging on a 1.5-T system (Philips Medical Systems, Gyroscan Intera, Best, The Netherlands) using a phased array pelvic coil. Sequential images with an imaging time of 14.4s per dynamic image were acquired before and after injection of a contrast bolus at 30s and at 1, 2, 3, 4, and 5 min. On postprocessing examination the following measurements were obtained for ovarian and muscle tissue: the signal intensity value per dynamic study, early phase enhancement rate, time to peak enhancement (Tp), and percentage of wash-out at the fifth minute were determined. Data of the ovaries and skeletal muscle were compared using Wilcoxon's rank sum test. RESULTS: Most of the mean values of the postcontrast signal intensity measurements, the mean values of the early phase enhancement rate, and the percentage of wash-out at the fifth minute were found to be significantly higher in ovary than in muscle (p<0.05). The mean values of Tp, on the other hand, were nonsignificantly lower in ovary than in muscle (p>0.05). On the examination of the mean signal intensity-time data graphics the ovary showed a tendency toward greater and quicker enhancement and wash-out. CONCLUSION: In our opinion, DCE-MR imaging, which determines contrast enhancement such as wash-in and wash-out kinetics, can provide knowledge of ovarian vascularization. Thus, by using DCE-MR imaging, determination of these vascularization changes in various ovarian diseases may provide us with additional parameters in the diagnosis of and treatment strategies for ovarian diseases.

Degenerative disc disease of the lumbar spine: a prospective comparison of fast T1-weighted fluid-attenuated inversion recovery and T1-weighted turbo spin echo MR imaging.

OBJECTIVE: To compare fast T1-weighted fluid-attenuated inversion recovery (FLAIR) and T1-weighted turbo spin-echo (TSE) imaging of the degenerative disc disease of the lumbar spine. MATERIALS AND METHODS: Thirty-five consecutive patients (19 females, 16 males; mean age 41 years, range 31-67 years) with suspected degenerative disc disease of the lumbar spine were prospectively evaluated. Sagittal images of the lumbar spine were obtained using T1-weighted TSE and fast T1-weighted FLAIR sequences. Two radiologists compared these sequences both qualitatively and quantitatively. RESULTS: On qualitative evaluation, CSF nulling, contrast at the disc-CSF interface, the disc-spinal cord (cauda equina) interface, and the spinal cord (cauda equina)-CSF interface of fast T1-weighted FLAIR images were significantly higher than those for T1-weighted TSE images (P<0.001). On quantitative evaluation of the first 15 patients, signal-to-noise ratios of cerebrospinal fluid of fast T1-weighted FLAIR imaging were significantly lower than those for T1-weighted TSE images (P<0.05). Contrast-to-noise ratios of spinal cord/CSF and normal bone marrow/disc for fast T1-weighted FLAIR images were significantly higher than those for T1-weighted TSE images (P<0.05). CONCLUSION: Results in our study have shown that fast T1-weighted FLAIR imaging may be a valuable imaging modality in the armamentarium of lumbar spinal T1-weighted MR imaging, because the former technique has definite superior advantages such as CSF nulling, conspicuousness of the normal anatomic structures and changes in the lumbar spinal discogenic disease and image contrast and also almost equally acquisition times.

Magnetic resonance neurography diagnosed brachial plexitis: a case report.

Idiopathic brachial plexitis is a rare disorder presenting with pain and weakness in the shoulder girdle and upper extremity. Idiopathic brachial plexitis can mimic other conditions that cause acute pain and weakness around the shoulder, and its diagnosis can be challenging. There is no special test for the diagnosis of idiopathic brachial plexitis, although electromyography may be useful. In this case of idiopathic brachial plexitis, we present magnetic resonance neurography findings for the first time.

MR imaging features of foot involvement in ankylosing spondylitis.

OBJECTIVE: To determine alterations of the soft tissue, tendon, cartilage, joint space, and bone of the foot using magnetic resonance (MR) imaging in ankylosing spondylitis (AS) patients. MATERIALS AND METHOD: Clinical and MR examination of the foot was performed in 23 AS patients (46 feet). Ten asymptomatic volunteers (20 feet) were studied on MR imaging, as a control group. MR imaging protocol included; T1-weighted spin-echo, T2-weighted fast-field echo (FFE) and fat-suppressed short tau inversion recovery (STIR) sequences in sagittal, sagittal oblique, and coronal planes using a head coil. Specifically, we examined: bone erosions, tendinitis (acute and chronic), para-articular enthesophyte, joint effusion, plantar fasciitis, joint space narrowing, soft tissue edema, bone marrow edema, enthesopathy in the Achilles tendon and plantar fascia attachment, subchondral signal intensity abnormalities (edema and sclerosis), tenosynovitis, retrocalcaneal bursitis, subchondral cysts, subchondral fissures, and bony ankylosis. Midfoot, hindfoot, and ankle were included in examined anatomic regions. RESULTS: Clinical signs and symptoms (pain and swelling) due to foot involvement were present in 3 (13%) of the patients while frequency of involvement was 21 (91%) with MR imaging assessment. The MR imaging findings were bone erosions (65%), Achilles tendinitis (acute and chronic) (61%), para-articular enthesophyte (48%), joint effusion (43%), plantar fasciitis (40%), joint space narrowing (40%), subchondral sclerosis (35%), soft tissue edema (30%), bone marrow edema (30%), enthesopathy of the Achilles attachment (30%), subchondral edema (26%), enthesopathy in the plantar fascia attachment (22%), retrocalcaneal bursitis (22%), subchondral cysts (17%), subchondral fissures (17%), tendinitis and enthesopathy of the plantar ligament (13%), and bony ankylosis (9%). The most common involved anatomical region was the hindfoot (83%) following by midfoot (69% ) and ankle (22%). CONCLUSION: In our experience, MR imaging may detect inflammatory and/or erosive bone, soft tissue, cartilage, tendon, and joint abnormalities in AS patients, even if AS patients did not have clinical signs and symptoms of foot involvement. If these data prove to be confirmed in further MR studies, MR imaging may be of importance especially in early diagnosis of inflammatory changes in the foot.

[The role of three dimensional MR myelography in lumbar discogenic disease]. / Lomber disk hastaliginda üç boyutlu MR myelografinin yeri.

PURPOSE: To evaluate the role of the three dimensional (3D) MR myelography (MRM) in the diagnosis of the lumbar discogenic disease compared with conventional MR imaging. MATERIALS AND METHODS: Fifty consecutive patients with clinical symptoms of lumbar disc herniation were enrolled for the study. Conventional MR imaging and coronal 3D MRM were performed on a 1.5 T MR system. At each disc space level, the presence and the location of disc herniation and nerve root compression were evaluated. Note was also made if MRM had additional contribution to the determination of most significant level in the cases of multilevel disc disease and lumbar spinal stenosis. RESULTS: Disc herniation was found in 60 disc space levels on conventional MR imaging and in 54 disc space levels on 3D-MRM imaging. As regards to disc herniation, the sensitivity, specificity, and accuracy of 3D-MRM was 90%, 100%, and 96%, respectively. Nerve root compression was seen in 91 levels on conventional MR images, as opposed to 98 on 3D-MRM. Regarding nerve root compression, the sensitivity, specificity, and accuracy of 3D-MRM was 100%, 97%, and 98%, respectively. In all of 13 patients with multilevel disc disease and lumbar spinal stenosis, 3D-MRM had additional contribution. CONCLUSION: Scan time of 3D-MRM is short. It can be easily added to routine lumbar MR imaging. It may be a valuable modality in the diagnosis of the lumbar discogenic disease. The presence of false-negative and false-positive examinations necessitates caution in interpreting 3D-MRM images. 3D MRM technique may be useful in selected cases such as patients with multilevel disc abnormalities or lumbar spinal stenosis where it allows a rapid and easy appreciation of the level most likely to account for the pathology.

Polycystic ovary syndrome: dynamic contrast-enhanced ovary MR imaging.

OBJECTIVE: to determine the enhancement behaviour of the ovaries in women with polycystic ovary syndrome (PCOS) by dynamic contrast-enhanced magnetic resonance (DCE-MR) imaging and to compare these data with those of normal ovulating controls. METHOD: 24 women with PCOS and 12 controls underwent DCE-MR imaging. Dynamic images were acquired before and after injection of a contrast bolus at 30 s and the min of 1, 2, 3, 4 and 5. On postprocessing examination: (i) the ovarian volumes; (ii) the signal intensity value of each ovary per dynamic study; (iii) early-phase enhancement rate; (iv) time to peak enhancement (T(p)); and (v) percentage of washout of 5th min were determined. Data of the ovaries of the women with PCOS and controls were compared with Mann-Whitney U-test. RESULTS: the mean values of T(p) were found to be significantly lower in women with PCOS than in controls (p < 0.05). On the other hand, the mean values of ovarian volume, the early-phase enhancement rate, and percentage of washout of 5th min of ovaries were significantly higher in PCOS patients (p < 0.05). Examination of the mean signal intensity-time curve revealed the ovaries in women with PCOS showed a faster and greater enhancement and wash-out. CONCLUSION: the enhancement behaviour of ovaries of women with PCOS may be significantly different from those of control subjects on DCE-MR imaging examination. In our experience, it is a valuable modality to highlight the vascularization changes in ovarian stroma with PCOS. We believe that improved DCE-MR imaging techniques may also provide us additional parameters in the diagnosis and treatment strategies of PCOS.

Improved efficacy and tolerability of retinoic acid in acne vulgaris: a new topical formulation with cyclodextrin complex psi.

OBJECTIVES: Retinoic acid (RA) has long been used, both topically and systemically, for disorders of keratinization, acne and related disorders. In the present study, the efficacy and tolerability of topical RA prepared as a cyclodextrin beta complex (beta-CD) is investigated in 66 acne vulgaris patients. METHODS: This randomized, double-blind, placebo-controlled study compares nightly topical application of RA/beta-CD complex hydrogel formulation (0.025%), RA/beta-CD complex in moisturizing base (0.025%), hydrogel base, moisturizer base or a commercial RA gel (0.05%) in acne vulgaris patients. Improvement of acne was assessed using a 5-point improvement scale and by measuring sebum and moisture content of the skin using an SM 810 sebumeter/corneometer. RESULTS: After 3 months of treatment, mean scores of acne improvement on the 5-point scale were 4 with the RA/beta-CD complex hydrogel formulation, 4.1 with the RA/beta-CD complex in moisturizing base, 1.2 with hydrogel placebo base, 1.1 with moisturizer placebo base and 3 with the commercial RA product. All patients treated with the commercial product experienced local side-effects. One patient discontinued due to severe irritation. None of the patients treated with the RA/beta-CD complex in the moisturizing base and hydrogel formulation experienced significant local irritation, although the sebum content of the skin decreased after application of the RA/beta-CD preparations. This change was not significant compared to controls. The moisture content of the skin was better preserved in the group treated with the RA/beta-CD complex in the moisturizing base. CONCLUSION: The topical RA/beta-CD complex, in hydrogel and moisturizing base, was more effective than the twice concentrated commercial RA product. There were few topical side-effects with this new formulation, which increases patient compliance. Topical RA/beta-CD (0.025% RA) did not significantly reduce sebum secretion but may help to preserve optimum epidermal moisture content with the proper base formulation. This is the first study in the literature reporting efficacy and tolerability of the topical RA/beta-CD complex in acne vulgaris. We conclude that the topical RA/beta-CD complex displays an improved efficacy and tolerability profile and is an effective treatment alternative for acne vulgaris.

Radiologic aspects of abdominal hydatidosis in children: a study of 31 cases in Turkey.

OBJECTIVE: To determine the location and radiological characteristics in children with abdominal hydatid disease (HD). MATERIALS AND METHODS: Thirty-one children (average age: 7.2 years) with abdominal HD were studied. The number, location, diameter and internal architecture of the cysts were assessed with abdominal ultrasonography (US) and computed tomography (CT). Density measurements and enhancement patterns were determined on CT. RESULTS: Twenty-one children had hepatic HD. The remaining 10 children had both hepatic and extrahepatic cysts. There were splenic cysts in five children, peritoneal cysts in two children and combined splenic and peritoneal cysts in three children. The most common site of the cysts was the liver (64%), followed by the spleen (20%) and the peritoneal cavity (16%). The seven intraabdominal cysts, which were not detected by US, were 20 mm or less in diameter. CONCLUSION: CT may demonstrate additional small intrahepatic or unsuspected extrahepatic cysts. Although rare, splenic or peritoneal hydatidosis should be included in the differential diagnosis of a cystic splenic or peritoneal lesion. Familiarity with atypical locations of HD may be helpful in making a prompt, accurate diagnosis. We think that in particular patients, especially those who had diagnostic problem and who are under surgical planning, CT should be performed additionally.