Nanoarchitectured Design of Porous Materials and Nanocomposites from Metal-Organic Frameworks

The emergence of metal-organic frameworks (MOFs) as a new class of crystalline porous materials is attracting considerable attention in many fields such as catalysis, energy storage and conversion, sensors, and environmental remediation due to their controllable composition, structure and pore size. MOFs are versatile precursors for the preparation of various forms of nanomaterials as well as new multifunctional nanocomposites/hybrids, which exhibit superior functional properties compared to the individual components assembling the composites. This review provides an overview of recent developments achieved in the fabrication of porous MOF-derived nanostructures including carbons, metal oxides, metal chalcogenides (metal sulfides and selenides), metal carbides, metal phosphides and their composites. Finally, the challenges and future trends and prospects associated with the development of MOF-derived nanomaterials are also examined.

Seedless Synthesis of Monodispersed Gold Nanorods with Remarkably High Yield: Synergistic Effect of Template Modification and Growth Kinetics Regulation

Gold nanorods (AuNRs) are versatile materials due to their broadly tunable optical properties associated with their anisotropic feature. Conventional seed-mediated synthesis is, however, not only limited by the operational complexity and over-sensitivity towards subtle changes of experimental conditions but also suffers from low yield (≈15 %). A facile seedless method is reported to overcome these challenges. Monodispersed AuNRs with high yield (≈100 %) and highly adjustable longitudinal surface plasmon resonance (LSPR) are reproducibly synthesized. The parameters that influence the AuNRs growth were thoroughly investigated in terms of growth kinetics and soft-template regulation, offering a better understanding of the template-based mechanism. The facile synthesis, broad tunability of LSRP, high reproducibility, high yield, and ease of scale-up make this method promising for the future mass production of monodispersed AuNRs for applications in catalysis, sensing, and biomedicine.

Dual-Phase Transformation: Spontaneous Self-Template Surface-Patterning Strategy for Ultra-transparent VO2 Solar Modulating Coatings

Dual-phase transformation has been developed as a template-free surface patterning technique in this study. Ordered VO₂ honeycomb structures with a complex hierarchy have been fabricated via this method, and the microstructures of the obtained VO₂(M) coatings are tunable by tailoring the pertinent variables. The VO₂(M) honeycomb-structured coatings have excellent visible light transmittance at 700 nm (T_vis) up to 95.4% with decent solar modulating ability (ΔT_sol) of 5.5%, creating the potential as ultratransparent smart solar modulating coatings. Its excellent performance has been confirmed by a proof-of-principle demonstration. The dual-phase transformation technique has dramatically simplified the conventional colloidal lithography technique as a scalable surface patterning technique for achieving high-performance metal oxide coatings with diverse applications, such as catalysis, sensing, optics, electronics, and superwettable materials.

Superwettability Strategy: 1D Assembly of Binary Nanoparticles as Gas Sensors

Binary 1D nanowires consisting of both SnO₂ nanoparticles and Au nanorods are fabricated through a "substrate-particle solution template" assembling method, which shows highly enhanced gas sensitivity toward acetone under ambient conditions.

Operator variability in scan positioning is a major component of HR-pQCT precision error and is reduced by standardized training

In this study, we determined that operator positioning precision contributes significant measurement error in high-resolution peripheral quantitative computed tomography (HR-pQCT). Moreover, we developed software to quantify intra- and inter-operator variability and demonstrated that standard positioning training (now available as a web-based application) can significantly reduce inter-operator variability.

INTRODUCTION

HR-pQCT is increasingly used to assess bone quality, fracture risk, and anti-fracture interventions. The contribution of the operator has not been adequately accounted in measurement precision. Operators acquire a 2D projection ("scout view image") and define the region to be scanned by positioning a "reference line" on a standard anatomical landmark. In this study, we (i) evaluated the contribution of positioning variability to in vivo measurement precision, (ii) measured intra- and inter-operator positioning variability, and (iii) tested if custom training software led to superior reproducibility in new operators compared to experienced operators.

METHODS

To evaluate the operator in vivo measurement precision, we compared precision errors calculated in 64 co-registered and non-co-registered scan-rescan images. To quantify operator variability, we developed software that simulates the positioning process of the scanner's software. Eight experienced operators positioned reference lines on scout view images designed to test intra- and inter-operator reproducibility. Finally, we developed modules for training and evaluation of reference line positioning. We enrolled six new operators to participate in a common training, followed by the same reproducibility experiments performed by the experienced group.

RESULTS

In vivo precision errors were up to threefold greater (Tt.BMD and Ct.Th) when variability in scan positioning was included. The inter-operator precision errors were significantly greater than the short-term intra-operator precision (p < 0.001). New trained operators achieved comparable intra-operator reproducibility to experienced operators and lower inter-operator reproducibility (p < 0.001). Precision errors were significantly greater for the radius than for the tibia.

CONCLUSION

Operator reference line positioning contributes significantly to in vivo measurement precision and is significantly greater for multi-operator datasets. Inter-operator variability can be significantly reduced using a systematic training platform, now available online ( http://webapps.radiology.ucsf.edu/refline/ ).

MR Fingerprinting of Adult Brain Tumors: Initial Experience

BACKGROUND AND PURPOSE

MR fingerprinting allows rapid simultaneous quantification of T1 and T2 relaxation times. This study assessed the utility of MR fingerprinting in differentiating common types of adult intra-axial brain tumors.

MATERIALS AND METHODS

MR fingerprinting acquisition was performed in 31 patients with untreated intra-axial brain tumors: 17 glioblastomas, 6 World Health Organization grade II lower grade gliomas, and 8 metastases. T1, T2 of the solid tumor, immediate peritumoral white matter, and contralateral white matter were summarized within each ROI. Statistical comparisons on mean, SD, skewness, and kurtosis were performed by using the univariate Wilcoxon rank sum test across various tumor types. Bonferroni correction was used to correct for multiple-comparison testing. Multivariable logistic regression analysis was performed for discrimination between glioblastomas and metastases, and area under the receiver operator curve was calculated.

RESULTS

Mean T2 values could differentiate solid tumor regions of lower grade gliomas from metastases (mean, 172 ± 53 ms, and 105 ± 27 ms, respectively; P = .004, significant after Bonferroni correction). The mean T1 of peritumoral white matter surrounding lower grade gliomas differed from peritumoral white matter around glioblastomas (mean, 1066 ± 218 ms, and 1578 ± 331 ms, respectively; P = .004, significant after Bonferroni correction). Logistic regression analysis revealed that the mean T2 of solid tumor offered the best separation between glioblastomas and metastases with an area under the curve of 0.86 (95% CI, 0.69-1.00; P < .0001).

CONCLUSIONS

MR fingerprinting allows rapid simultaneous T1 and T2 measurement in brain tumors and surrounding tissues. MR fingerprinting-based relaxometry can identify quantitative differences between solid tumor regions of lower grade gliomas and metastases and between peritumoral regions of glioblastomas and lower grade gliomas.

Body fat differences by self-reported race/ethnicity in healthy term newborns

BACKGROUND

Ethnic differences in total body fat (fat mass [FM]) have been reported in adults and children, but the timing of when these differences manifest and whether they are present at birth are unknown.

OBJECTIVES

This study aimed to assess whether ethnic differences in body fat are present at birth in healthy infants born at term, where body fat is measured using air displacement plethysmography and fat distribution by skin-fold thickness.

METHODS

Data were from a multiracial cross-sectional convenience sample of 332 term infants from four racial or ethnic groups based on maternal self-report (A, Asian; AA, non-Hispanic Black [African-American]; C, non-Hispanic White; and H, Hispanic). The main outcome measure was infant body fat at 1-3 days after birth, with age, birth weight, gestational age and maternal pre-pregnancy weight as covariates.

RESULTS

Significant effects for race (P = 0.0011), sex (P = 0.0051) and a race by sex interaction (P = 0.0236) were found. C females had higher FM than C males (P = 0.0001), and AA females had higher FM than AA males (P = 0.0205). C males had less FM than A males (P = 0.0353) and H males (P = 0.0001).

CONCLUSION

Race/ethnic and sex differences in FM are present in healthy term newborns. Although the implications of these differences are unclear, studies beginning in utero and birth set the stage for a life course approach to understanding disease later in life.

Longitudinal analysis of cartilage T2 relaxation times and joint degeneration in African American and Caucasian American women over an observation period of 6 years - data from the Osteoarthritis Initiative

OBJECTIVES

To investigate the change in cartilage T2 values and structural degeneration in knee joints over 72 months in women of African American (AA) vs Caucasian American (CA) ethnicity.

METHODS

Knee 3T magnetic resonance imaging (MRIs) from baseline, 24, 48 and 72 months visits of 100 AA and 100 CA women from the Osteoarthritis Initiative (OAI) were assessed for cartilage T2 values and whole-organ magnetic resonance imaging (WORMS) score. Subjects were pair-matched by age, body mass index (BMI), Kellgren-Lawrence (KL) score, clinical site and subcohort within the OAI. We compared the rate of change in whole knee cartilage T2 values and WORMS cartilage, bone marrow edema pattern (BMEP) and meniscus scores between the two ethnic groups using mixed random effects models.

RESULTS

At 24 and 48 months 60 subjects and at 72 months 45 subjects per group were available for analysis resulting in 38 complete pairs with data of all time points. Compared to CA, cartilage T2 values in AA increased at a significantly faster rate at baseline (AA: 0.45 ms/y, CA: 0.35 ms/y, P = 0.029) and averaged over 6 years (AA: 0.36 ms/y, CA: 0.27 ms/y, P = 0.039) with changes in both groups reaching a plateau by 48 months. Cartilage, meniscus and BMEP scores tended to increase in both groups during follow up, but rates of change did not differ by ethnicity.

CONCLUSION

Cartilage T2 values increased faster over 72 months in AA than CA, however changes in WORMS cartilage, meniscus and BMEP scores did not differ. T2 values may be able to distinguish ethnicity-related differences of cartilage degeneration at an early stage before differences in structural joint degeneration appear.

Physiology and Pathophysiology of Sodium Channel Inactivation

Voltage-gated sodium channels are present in different tissues within the human body, predominantly nerve, muscle, and heart. The sodium channel is composed of four similar domains, each containing six transmembrane segments. Each domain can be functionally organized into a voltage-sensing region and a pore region. The sodium channel may exist in resting, activated, fast inactivated, or slow inactivated states. Upon depolarization, when the channel opens, the fast inactivation gate is in its open state. Within the time frame of milliseconds, this gate closes and blocks the channel pore from conducting any more sodium ions. Repetitive or continuous stimulations of sodium channels result in a rate-dependent decrease of sodium current. This process may continue until the channel fully shuts down. This collapse is known as slow inactivation. This chapter reviews what is known to date regarding, sodium channel inactivation with a focus on various mutations within each NaV subtype and with clinical implications.

Abstract P1-14-17: Pathologic complete response rate with doxorubicin and cyclophosphamide followed by weekly paclitaxel with trastuzumab and pertuzumab in patients with HER2-positive early stage breast cancer: A single institution experience

Background:

Trastuzumab and pertuzumab (HP) with standard chemotherapy is approved for use in the neoadjuvant setting. We performed a retrospective analysis of patients (pts) treated with dose-dense doxorubicin and cyclophosphamide (AC) → paclitaxel, trastuzumab, pertuzumab (THP) in the neoadjuvant setting. Here we report the pathologic complete response (pCR) rate.

Methods:

We abstracted medical records of patients who were treated with pertuzumab-based therapy in the neoadjuvant setting from September 1, 2013 to March 1, 2015. Charts were analyzed for pt demographics, stage of breast cancer, pathology reports, surgical data, and information on systemic therapy.

Results:

Charts from 66 pts were reviewed; 60 pts were evaluable for pCR defined as absence of invasive disease in the breast, and 6 were not (3-no anthracycline, 1-incomplete chart, 1-no surgery yet, 1-metastatic). Median age was 47 years (range 28-68 years). Of 60 pts, 52 (86%) had operable breast cancer (T1-3, N0-1, M0) of which 7 had clinical stage I disease (T1N0)]; 7 (12%) had locally advanced disease (T2-3, N2-3, M0 or T4a-c, any N, M0), and 1 (2%) had inflammatory breast cancer (T4d, any N, M0). 49 (82%) and 11 (18%) had hormone receptor (HR)-positive and negative diseases, respectively. All patients had HER2-positive breast cancer defined as immunohistochemistry (IHC) 3+ and/or fluorescent in-situ hybridization (FISH) of &gt; 2.0. 30 pts (50%) underwent mastectomy and lumpectomy, respectively. Out of 60 evaluable pts, 41 (68%) had pCR; 32/49 (65%) with HR-positive and 9/11 (82%) with HR-negative diseases had pCR, respectively. Overall 58/60 (97%) pts completed neoadjuvant therapy; 2 did not (1 developed Steven Johnson Syndrome after one cycle of AC and 1 developed pneumonitis after third weekly dose of T with HP).

Conclusions:

At our single center experience the pCR rate of dose dense AC→THP is high at 68 %. These data are similar to results seen in the TRYPHAENA study, and we await the results from the BERENICE trial evaluating pCR as a secondary endpoint.

Patient Demographics Age, years &lt;4525 (42%)45-5419 (32%)&gt;5516 (26%) ECOG Performace Status 031 (52%)129 (48%) Hormone receptor (HR) status HR+ Her2+49 (82%)HR- Her2+11 (18%) Status of Her-2 Positivity IHC positive52 (86%)FISH positive8 (14%) Median tumor size2.6cm (range: 1-8.4cm) Stage Operable (T1-2, N0-1, M0)52 (86%)Operable Stage I7 (12%)Operable Stage II/III45 (74%)Locally advanced (T2-3, N2-3, M0 or T4a-c, any N, M0))7 (12%)Inflammatory (T4d, any N, M0)1 (2%) Type of surgery Lumpectomy30 (50%)Mastectomy30 (50%)

Citation Format: Singh JC, Sugarman S, Jones L, Boafo C, Patil S, Schweber S, Yu A, Argolo D, Modi S, Iyengar N, Smyth L, Norton L, Baselga J, Hudis C, Dang C. Pathologic complete response rate with doxorubicin and cyclophosphamide followed by weekly paclitaxel with trastuzumab and pertuzumab in patients with HER2-positive early stage breast cancer: A single institution experience. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-14-17.

Engineering silicon crystals for photovoltaics

In this highlight, we review the recent engineering efforts in the state-of-the art industrial production of customized silicon crystals, including quasi-mono and multi-crystalline silicon (mc-Si).