In locations that lack nearby cyclotron facilities for radionuclide production, generator-based
68Ga radiopharmaceuticals might have clinical utility for positron emission tomography (PET) studies of ...myocardial perfusion and other physiological processes.
The lipophilic and monocationic
67Ga-labeled gallium chelates of five novel hexadentate
bis(salicylaldimine) ligands the
bis(salicylaldimine),
bis(3-methoxysalicylaldimine),
bis(4-methoxysalicylaldimine),
bis(6-meth,oxysalicylaldimine), and
bis(4,6-dimethoxysalicylaldimine) of
N,
N′-
bis(3-aminopropyl)
-N,
N′
-dimethylethylenediamine (BAPDMEN), were prepared. The structure of the unlabeled Ga(4-MeOsal)
2BAPDMEN
+PF
6
− salt was determined by X-ray crystallography, and the biodistribution of each of the
67Ga-labeled gallium chelates was determined in rats following intravenous administration and compared with the biodistribution of
86Rbrubidium chloride.
The Ga(4-MeOsal)
2BAPDMEN
+PF
6
− complex exhibited the expected pseudo-octahedral N
4O
2
2− coordination sphere about the Ga
3+ center with a
trans disposition of the phenolate oxygen atoms. All five
67Ga radiopharmaceuticals were found to afford the desired myocardial retention of the radiogallium. The
67/68GaGa(3-MeOsal)
2BAPDMEN
1+ radiopharmaceutical appears to have the best properties for myocardial imaging, exhibiting 2% of the injected dose in the heart 1 min and 2 h postinjection and very high heart/nontarget ratios (heart/blood ratios of 7.6±1.0 and 54±10 at 1 and 120 min, respectively; heart/liver ratios of 1.8±0.4 and 39±3 at 1 and 120 min, respectively).
Most of these new agents, particularly
67/68GaGa(3-MeOsal)
2BAPDMEN
1+, would appear superior to previously reported
bis(salicylaldimine) ligands of
N,
N′-
bis(3-aminopropyl)ethylenediamine as candidates for PET imaging of the heart with
68Ga.
We present a new class of colossal magnetoresistance materials based on a series of frustrated spinels. The spin glass-like compound Zn0.95Cu0.05Cr2Se4, shows a field-induced transition to a ...ferromagnetic, which is associated with a highly unusual negative magnetoresistance effect (MR > 80%) in low magnetic field. At higher temperatures there is an unprecedented crossover to positive magnetoresistance (MR > 50%).
In the Alzheimer's disease (AD) continuum, the prodromal state of mild cognitive impairment (MCI) precedes AD dementia and identifying MCI individuals at risk of progression is important for clinical ...management. Our goal was to develop generalizable multivariate models that integrate high-dimensional data (multimodal neuroimaging and cerebrospinal fluid biomarkers, genetic factors, and measures of cognitive resilience) for identification of MCI individuals who progress to AD within 3 years. Our main findings were i) we were able to build generalizable models with clinically relevant accuracy (~93%) for identifying MCI individuals who progress to AD within 3 years; ii) markers of AD pathophysiology (amyloid, tau, neuronal injury) accounted for large shares of the variance in predicting progression; iii) our methodology allowed us to discover that expression of CR1 (complement receptor 1), an AD susceptibility gene involved in immune pathways, uniquely added independent predictive value. This work highlights the value of optimized machine learning approaches for analyzing multimodal patient information for making predictive assessments.
•Traditional site index (tree height at base age) may not be suitable for urban trees.•Rapid and non-destructive tree age evaluation methods need to be developed.•Loblolly pine tree age was ...determined using a minimally-invasive recording resistance drill based technique.•The method allowed rapid evaluation of tree age across an urban forest.
Conventional site index (tree height at base age) may not be suitable for urban trees, therefore it is important to assess its applicability in urban environments. In addition, rapid and non-destructive tree age evaluation methods need to be developed. The objectives of this study were to: (1) develop a rapid and non-destructive method to determine tree age in urban environments, (2) examine the relationship between tree height, age, location, and soil type, and (3) compare the measured site indices with traditional site indices reported in Soil Survey Geographic Database (SSURGO). The study was conducted at the Clemson Experimental Forest (CEF) using conventionally-managed loblolly pine (Pinus taeda) stands, and loblolly pines in the urban environment of the Clemson University campus (CUC). Tree age obtained with a recording resistance drilling method and stump tree ring counting were comparable (R2 = 0.98, n = 14). Tree age estimates from recording resistance drilling and from increment boring were also similar (R2 = 0.93, n = 25). Replicate drilling samples had a low standard deviation, which indicated the high precision of the methodology. An additional benefit of the recording resistance drilling method is the ability to enable rapid evaluation of tree age across an urban forest. There was no discernible relationship between tree height and recording resistance drill age estimate for loblolly pines on the CUC (n = 25). In contrast, there was a relationship between measured diameter at breast height (DBH, cm) and recording resistance drill age estimates. A portion of the loblolly pine trees in the urban environment on the CUC appeared to have reduced productivity, as measured by the height/age relationship when predominantly surrounded by pavement or grass areas.
This study investigates the effects of diet-induced changes in maternal body condition on glucose tolerance in sheep. Welsh Mountain ewes were established, by dietary manipulation, at a body ...condition score of 2 (lower body condition LBCS, n = 17) or >3 (higher body condition HBCS, n = 19) prior to and during pregnancy. Birth weight and postnatal growth were similar in LBCS and HBCS offspring. In young adulthood, LBCS offspring had increased fasting glucose levels (3.8 +/- 0.07 vs 3.6 +/- 0.05 mM, P < .05), poorer glucose tolerance (2274 +/- 22.6 vs 2161 +/- 33 min/mM, P < .01), and reduced insulin secretion (0.58 +/- 0.05 vs 0.71 +/- 0.07 nM/min, P = .07). Increased fasting glycemia, mild glucose intolerance, and impaired initial insulin secretory response, as observed in LBCS offspring, are indictors of increased diabetes risk in humans. These findings suggest that altered maternal body composition and an imbalance between the fetal and postnatal environment influence offspring glucose tolerance.
68GaGa-DOTA-NOC was produced under an Expanded Access IND for 174 clinical PET/CT studies to evaluate patients with neuroendocrine tumors. Production employed either the TiO2-based Eckert & Ziegler ...(EZAG) 68Ge/68Ga-generator (with fractionated elution), or the SiO2-based ITG 68Ge/68Ga-generator. In both cases, 68GaGa-DOTA-NOC was reliably produced, without pre-synthesis purification of the68Ga generator eluate, using readily-implemented manual synthesis procedures. 68GaGa-DOTA-NOC radiochemical purity averaged 99.2±0.4%. Administered 68Ga dose averaged 181±22 MBq, and administered peptide mass averaged 43.2±5.2µg (n=47) and 23.9±5.7µg (n=127), respectively, using the EZAG and ITG generators. At dose expiration, 68Ge breakthrough in the final product averaged 2.7×10−7% and 5.4×10−5% using the EZAG and ITG generators, respectively.
•68GaGa-DOTA-NOC was produced for clinical use under the Expanded Access IND mechanism.•Start-up and operating costs were minimized via a manual approach to synthesis.•The ITG and Eckert & Ziegler 68Ga-generators both provided acceptable performance.•Radiopharmaceutical synthesis did not require pre-purification of the generator eluate.•68GaGa-DOTA-NOC was reliably provided at high radiochemical purity (99.2±0.4%).
Ptychographic X-ray computed tomography visualizes the effects crystallography and solution composition have on occlusion motif and occlusion density of crystalline nanocomposites.
Single crystals ...containing nanoparticles represent a unique class of nanocomposites whose properties are defined by both their compositions and the structural organization of the dispersed phase in the crystalline host. Yet, there is still a poor understanding of the relationship between the synthesis conditions and the structures of these materials. Here ptychographic X-ray computed tomography is used to visualize the three-dimensional structures of two nanocomposite crystals – single crystals of calcite occluding diblock copolymer worms and vesicles. This provides unique information about the distribution of the copolymer nano-objects within entire, micron-sized crystals with nanometer spatial resolution and reveals how occlusion is governed by factors including the supersaturation and calcium concentration. Both nanocomposite crystals are seen to exhibit zoning effects that are governed by the solution composition and interactions of the additives with specific steps on the crystal surface. Additionally, the size and shape of the occluded vesicles varies according to their location within the crystal, and therefore the solution composition at the time of occlusion. This work contributes to our understanding of the factors that govern nanoparticle occlusion within crystalline materials, where this will ultimately inform the design of next generation nanocomposite materials with specific structure/property relationships.
The National High Blood Pressure Education Program's Working Group on High Blood Pressure in Pregnancy recently issued a report implicating hypertension as a complication in 6 to 8 percent of ...pregnancies. Hypertension in pregnancy is related to one of four conditions: (1) chronic hypertension that predates pregnancy; (2) preeclampsia-eclampsia, a serious, systemic syndrome of elevated blood pressure, proteinuria and other findings; (3) chronic hypertension with superimposed preeclampsia; and (4) gestational hypertension, or nonproteinuric hypertension of pregnancy. Edema is no longer a criterion for preeclampsia, and the definition of blood pressure elevation is 140/90 mm Hg or higher. Patients with gestational hypertension have previously unrecognized chronic hypertension, emerging preeclampsia or transient hypertension of pregnancy, an obstetrically benign condition. Because distinguishing among these conditions can be done only in retrospect, clinical management of gestational hypertension consists of repeated evaluations to look for signs of emerging preeclampsia. Women with chronic hypertension should be followed for evidence of fetal growth restriction or superimposed preeclampsia. Management options for chronic hypertension in most women include discontinuing antihypertensive medications during pregnancy, switching to methyldopa or continuing previous antihypertensive therapy.
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