Pick and place process for uniform shrinking of 3D printed micro- and nano-architected materials.

Two-photon polymerization lithography is promising for producing three-dimensional structures with user-defined micro- and nanoscale features. Additionally, shrinkage by thermolysis can readily shorten the lattice constant of three-dimensional photonic crystals and enhance their resolution and mechanical properties; however, this technique suffers from non-uniform shrinkage owing to substrate pinning during heating. Here, we develop a simple method using poly(vinyl alcohol)-assisted uniform shrinking of three-dimensional printed structures. Microscopic three-dimensional printed objects are picked and placed onto a receiving substrate, followed by heating to induce shrinkage. We show the successful uniform heat-shrinking of three-dimensional prints with various shapes and sizes, without sacrificial support structures, and observe that the surface properties of the receiving substrate are important factors for uniform shrinking. Moreover, we print a three-dimensional mascot model that is then uniformly shrunk, producing vivid colors from colorless woodpile photonic crystals. The proposed method has significant potential for application in mechanics, optics, and photonics.

Structural Colors on Al Surface via Capped Cu-Si3N4 Bilayer Structure.

Tunable structural colors have a multitude of applications in the beautification of mobile devices, in the decoration of artwork, and in the creation of color filters. In this paper, we describe a Metal-Insulator-Metal (MIM) design that can be used to systematically tune structural colors by altering the thickness of the top metal and intermediate insulator. Cu and Si3N4 were selected as the top metal and intermediate insulator layers, respectively, and various reflection colors were printed on Al. To protect the Cu surface from scratchiness and oxidation, a number of capping layers, including SiO2, LPSQ, PMMA, and the commercially available clear coat ProtectaClear, were applied. In addition to their ability to protect Cu from a humid environment without deteriorating color quality, ProtectaClear and LPSQ coatings have minimal angle dependency. Furthermore, a bilayer of PMMA/SiO2 can protect the Cu surface from the effects of humidity. In addition, the PMMA/SiO2 and ProtectaClear/SiO2 bilayers can also protect against corrosion on the Cu surface. The colors can be tuned by controlling the thickness of either the metal layer or intermediate insulator layer, and vivid structural colors including brown, dark orange, blue, violet, magenta, cyan, green-yellow, and yellow colors can be printed. The measured dielectric functions of Cu thin films do not provide any evidence of the plasmonic effect, and therefore, it is expected that the obtained colors are attributed to thin-film interference.

2D-Oriented Attachment of 1D Colloidal Semiconductor Nanocrystals via an Etchant.

The oriented attachment (OA) of 0D semiconductor nanocrystals into 1D and 2D nanostructures with unique properties is useful for the fabrication of quantum confined nanomaterials that are otherwise difficult to produce by direct synthesis. Given that the OA of 1D nanocrystals such as nanorods generally produces linear chains, rod-couple structures, or clustered columns, linking them in a facet-specific manner to produce 2D structures is challenging. Here, we report that 1D Cu2-xS nanorods undergo etching on exposure to hexylphosphonic acid under mild heating, which results in an increased curvature and a reduction in surface ligands at those sites. This causes the nanorods to fuse via their basal tip facets into chains and then cojoin through diametrically opposed side facets, resulting in atomically coupled, 2D raftlike structures. The stepwise OA of 1D nanocrystals into 2D nanostructures illustrated here expands the range of nanoarchitectures that can be produced via solution-processed methods.

Branched Heterostructured Semiconductor Nanocrystals with Various Branch Orders via a Facet-to-Facet Linking Process.

Branched heterostructured semiconductor nanoparticles such as core seeded tetrapods and octapods offer properties not seen in their spherical core-shell counterparts, but are challenging to synthesize with a large diversity of branch numbers via heterogeneous nucleation and growth processes alone. This work describes a process to facet-link matchstick-like Ag2S-tipped ZnS nanorods via their Ag2S tips, producing branched Ag2S-centered ZnS nanoparticles such as bipods, tripods, and in general multipods with 4 to 16 ZnS arms as a function of reaction time. The angle between nanorods in the bipods and tripods is found to be close to 120°, resulting in unexpected bent and trigonal planar geometry, respectively. This is attributed to the exposed facets of the monoclinic Ag2S tips, their relative chemical reactivities, and their atomic composition. The formation of particles with an increasing number of branches takes place in a stepwise manner, thus making the facet-linking approach a facile synthesis route to systematically obtaining a diverse set of branched heterostructured semiconductor nanoparticles with a well-defined number of branches.

Study of Gene Expression Profiles of Breast Cancers in Indian Women.

Breast cancer is the most common cancer among women globally. In India, the incidence of breast cancer has increased significantly during the last two decades with a higher proportion of the disease at a young age compared to the west. To understand the molecular processes underlying breast cancer in Indian women, we analysed gene expression profiles of 29 tumours and 9 controls using microarray. In the present study, we obtained 2413 differentially expressed genes, consisting of overexpressed genes such as COL10A1, COL11A1, MMP1, MMP13, MMP11, GJB2, and CST1 and underexpressed genes such as PLIN1, FABP4, LIPE, AQP7, LEP, ADH1A, ADH1B, and CIDEC. The deregulated pathways include cell cycle, focal adhesion and metastasis, DNA replication, PPAR signaling, and lipid metabolism. Using PAM50 classifier, we demonstrated the existence of molecular subtypes in Indian women. In addition, qPCR validation of expression of metalloproteinase genes, MMP1, MMP3, MMP11, MMP13, MMP14, ADAMTS1, and ADAMTS5 showed concordance with that of the microarray data; wherein we found a significant association of ADAMTS5 down-regulation with older age (≥55 years) of patients. Together, this study reports gene expression profiles of breast tumours from the Indian subcontinent, throwing light on the pathways and genes associated with the breast tumourigenesis in Indian women.

Posttransplant epithelioid inflammatory myofibroblastic sarcoma: A case report.

Epithelioid inflammatory myofibroblastic sarcoma (EIMS) is a rare entity and a novel variant of inflammatory myofibroblastic tumor (IMT), usually seen in children and nonsmoking young adults. Their occurrence in a posttransplant setting is still rare. These tumors are characterized by prominent epithelioid morphology, large histiocytoid "Reed Sternberg"-like cell, unique pattern of ALK immuno-reactivity, and aggressive clinical behavior. Their etiology and metastatic potential is controversial. In a post-transplant setting, many factors such as trauma, infections with EBV, HIV, Hepatitis C, mycobacteria, fungus, and chemotherapy-induced immunosuppression have been implicated in their etiology. We present the case of a 2-year-old female child who developed multiple omental and mesenteric tumor nodules, 8 months post liver transplant for progressive familial intrahepatic cholestasis (PFIC). Following a histopathological diagnosis of "mesenchymal neoplasm of possible malignant nature" on a trucut biopsy and frozen section, tumor debulking was performed. A final histological diagnosis of EMIS was made on the completely resected tumor. The patient remains in remission nearly 7 months after presentation, without any follow-up systemic chemotherapy. IMT after a solid organ transplant is rare, only 5 cases have been reported in the literature until now. Similar phenomenon has also been noted with hematopoietic stem cell transplant. However, to our knowledge, this case of EMIS in a post liver transplant patient is first of its kind.

Clinicopathological Evaluation of 223 Cases of Mature Cystic Teratoma, Ovary: 25-Year Experience in a Single Tertiary Care Centre in India.

INTRODUCTION: Mature Cystic Teratoma (MCT) is the most common benign neoplasm of the ovary constituting 10-20% of all the ovarian tumours. Although, much has been published about ovarian teratomas, in English literature, there are very few retrospective cross sectional studies from India to understand the epidemiology of the disease. AIM: To evaluate the prevalence, clinicopathological characteristics and complications of MCT of the ovary. MATERIALS AND METHODS: This was a retrospective study of 223 cases of MCT of ovary received over a period of 25 years from 1990 to 2014. The data regarding age, size, laterality, gross, morphological features, complications and surgery performed was retrieved from the archives of pathology department. Descriptive statistics was performed using SPSS software version 22 and the results were expressed as percentages. RESULTS: MCT constituted 20.2% of the total ovarian neoplasms and 78.5% of all the germ cell tumours. The mean age of the patients with MCT was 32.5±13.11 years and the mean size of tumour was 8.6±3.1 cm. Torsion was the most common complication of these tumours. Malignant transformation of this tumour though rare was seen in 3.5% of the cases. CONCLUSION: MCT are most common tumours of the ovary. Though predominantly seen in reproductive age group, they may also be seen in children and postmenopausal women. Torsion is the most common complication of this tumour. Age of the patient and the size of the tumour are important prognostic factors in terms of malignant transformation of teratomas. Since 8.9% of these tumours were bilateral it is essential to thoroughly examine the contralateral ovary to rule out bilaterality. Early diagnosis and early treatment is essential to preserve fertility in these patients.

Correlation of FOXL2 with Inhibin and Calretinin in the Diagnosis of Ovarian Sex Cord Stromal Tumors.

OBJECTIVE: Alpha-inhibin and calretinin have been traditionally used as immunomarkers for sex cord stromal tumors. However, the variation in their immunoreactivity and their lack of specificity for sex cord stromal tumor makes the search for a more sensitive and specific immunohistochemical marker essential in routine diagnosis of sex cord stromal tumor. This study was conducted to correlate the diagnostic utility of FOXL2 with inhibin and calretinin in the diagnosis of sex cord stromal tumors of ovary. MATERIAL AND METHOD: The study was conducted in the department of pathology. 31 cases of sex cord tumors received in past eight years (2002-2010) were included in this study. Immunostaining for inhibin, calretinin and FOXL2 was performed and compared on the basis of staining intensity and percentage positivity on all the cases. RESULTS: Calretinin was found to be positive in 29/31 sex cord stromal tumors with variable intensities and was negative in two cases of sex cord stromal tumors, inhibin was positive in 28/31 and only three cases had no cytoplasmic staining. All the 31 cases included in this study were positive for FOXL2 with variable staining intensities and percentage positivity. Ten cases of each surface epithelial and germ cell tumors were also negatively stained with FOXL2. CONCLUSION: In contrast to inhibin and calretinin, FOXL2 had a sensitivity and specificity of 100% for all the cases of sex cord stromal tumors included in this study.

Spectrum of Childhood and Adolescent Ovarian Tumors in India: 25 Years Experience at a Single Institution.

BACKGROUND: Ovarian tumour in children and adolescent girls form an uncommon but important part of gynaecological malignancies. They account for 1% of all the childhood malignancies and 8% of all abdominal tumours in children. Since the ovarian cysts are thought to arise from mature follicles, these tumours were considered to be infrequent in the paediatric population. AIM: The rarity of this condition prompted us to conduct this study and share our experience on the incidence and clinicopathological features of different ovarian tumours in girls up to 20 years of age observed in last 25 years at a single tertiary care hospital. MATERIAL AND METHODS: This was a retrospective study conducted in the Department of Pathology at a tertiary hospital, Delhi. All ovarian tumours up to the age of 20 years in the past 25 years (1990-2014) were included for the purpose of studying the clinicopathological aspects of ovarian tumours in this age group. Descriptive statistics for prevalence and age-wise prevalence was done. Chi-square test, to find an association between the age, laterality and size with malignancy was performed. RESULTS: We received a total of 1102 cases of ovarian tumours over the period of 25 years (1990 to 2014), of which 112 (10%) cases were seen in girls up to 20 years of age. The mean age of the patients was 15.3 ± 4 years. The most common presenting complaint was pain abdomen (46.4 %) There was a statistically significant correlation found between size and malignancy status of tumours in our study (p = 0.00). Of 112 cases of ovarian tumours, 39/112 (34.8%) were malignant and 73/112 (65.2%) were benign. Mature cystic teratoma (27.6%) was the most common type of benign tumour in this age group and immature teratomas were the most common type of malignant ovarian neoplasms. CONCLUSION: Premenarchal girls with ovarian masses may have varied presentations. Abdominal pain is the most common presenting complaint of young adolescent girls with adnexal masses. So the index of suspicion should be kept high and prompt investigations like ultrasound must be performed early to rule out such adnexal masses. Immature Teratoma was the most common malignant and mature cystic teratoma was the most common benign tumour in our study.

Diagnosis of sirenomelia in the first trimester.

Sirenomelia or "mermaid syndrome" is a rare congenital abnormality with an incidence of 1 in 60,000. We report a case diagnosed in the first trimester using two-dimensional, three-dimensional, and color Doppler ultrasound. With increasing emphasis on early diagnosis of fetal abnormalities, this case highlights the importance of looking for anomalies in the first trimester itself. In fact, the diagnosis of sirenomelia should be easier in the first trimester as severe oligohydramnios in later gestation hampers vision.

Scrotal leiomyosarcoma associated with bilateral epididymo-orchitis.

Leiomyosarcoma of the scrotum is a rare tumor. We report the case of a 60-year-old man who presented with bilateral testicular enlargement that was clinically misdiagnosed as a testicular tumor. The tumor was excised by bilateral inguinal orchiectomy. Histopathologic examination revealed a scrotal wall leiomyosarcoma with bilateral epididymo-orchitis.

Extraskeletal osteochondroma of the thigh: a case report.

A case of histopathologically proven extraskeletal osteochondroma of the thigh is presented along with its radiographic, CT and MRI findings. This is the first such case reported, to the best of our knowledge. The diagnosis of extraskeletal osteochondroma should be considered when a discrete ossified mass is localised in the soft tissue.