(C) 2011 American Institute of Physics. [doi: 10.1063/1.3552914]“
“Mefloquine is an effective and

widely used anti-malarial drug; however, some clinical reports suggest that it can cause dizziness, balance, and vestibular disturbances. To determine if mefloquine might be toxic to the vestibular system, we applied mefloquine to organotypic cultures of the macula of the utricle from postnatal day 3 rats. The macula of the utricle was micro-dissected out as a flat surface preparation and cultured with 10, 50, 100, or 200 mu M mefloquine for 24 h. Specimens were stained with TRITC-conjugated phalloidin to label the actin in hair cell stereocilia and TO-PRO-3 to visualize this website cell nuclei. Some utricles were also labeled with fluorogenic caspase-3, -8, or -9 indicators to evaluate the mechanism of programmed cell death. Mefloquine treatment caused a dose-dependent loss of utricular hair cells. Treatment with 10 mu M caused a slight reduction, 50 mu M caused a significant reduction, and 200 mu M destroyed nearly all the hair cells. Hair cell nuclei in mefloquine-treated utricles were condensed and fragmented, morphological features of apoptosis. GW3965 cost Mefloquine-treated utricles were positive for the extrinsic initiator caspase-8 and intrinsic initiator caspase-9 and downstream executioner caspase-3.

These results indicate that mefloquine can induce significant hair cell degeneration click here in the postnatal rat utricle and that mefloquine-induced hair cell death is initiated by both caspase-8 and caspase-9.”
“The choice of appropriate therapeutic plans for primary endocervical adenocarcinomas (ECA) and endometrial adenocarcinomas (EMA) depend on the tumor’s site of origin. The purpose of this study was to compare the performances of the commonly used three-marker (ER/Vim/CEA), four-marker (ER/Vim/CEA/PR) and five-marker (ER/Vim/CEA/PR/p16(INK4a)) panels in distinguishing

between primary ECA and EMA.

A tissue microarray was constructed using paraffin-embedded, formalin-fixed tissues from 35 hysterectomy specimens, including 14 ECA and 21 EMA. Utilizing the avidin-biotin (ABC) technique, tissue array sections were immunostained with five commercially available antibodies (ER, Vim, CEA, PR and p16(INK4a)) to evaluate the performances of their respective three-, four- and five-marker panels in distinguishing between primary ECA and EMA.

ER, PR and Vim were more likely to be expressed in EMA, while CEA and p16(INK4a) were frequently expressed in ECA. The three-marker (ER/Vim/CEA) panel exhibits the most favorable performance in the distinction between these two gynecologic malignancies (ECA vs. EMA).

And in the experiment the ethanol yield and other properties of the transformant Angel yeast F6 were similar to those of the wild-type strain, although its fermentation

time was a little slower comparing with the wild-type strain. Those would be potential application for yeast cells to separate and recycle in the fuel ethanol industry.”
“Sinus bradycardia is a well-known consequence of stimulation SCH727965 of presynaptic alpha(2) adrenergic receptors due the adminstration of dexmedetomidine. One of the most serious adverse effects of dexmedetomidine is cardiac arrest. Some cases demonstrating such an arrest due to the indiscriminate use of this drug were recently reported. We continuously administered dexmedetomidine to a 56-year-old male patient at a rate of 0.3 mu g/kg/h (lower than the recommended dose) without initial dosing for sedation in an intensive care unit. The patient had undergone open cardiac surgery and atrial pacing was maintained at a fixed rate, 90/min. The PQ interval in electrocardiography gradually prolonged during the infusion; finally, complete atrioventricular block and subsequent cardiac arrest

occurred. Immediate cardiopulmonary resuscitation was carried out, including re-intubation, and recovery of spontaneous circulation was attained 15 min after the event. The patient was discharged from hospital on the 25th postoperative day without any neurological complications.”
“Background:

The genes RAD51, BI 2536 order XRCC2 and XRCC3 encode proteins that are important for the repair of double-strand DNA breaks by homologous PD0325901 cell line recombination. Therefore, genetic variability in these genes may contribute to the occurrence and progression of endometrial cancer. Methods: The subject of investigation in the reported study was the distribution of genotypes and the prevalence of alleles of the RAD51 G135C, XRCC2 Arg188His and XRCC3 Thr241Met polymorphism in 230 cases of sporadic endometrial cancer; the polymorphisms were determined by polymerase chain reactionrestriction fragment-length polymorphism methods. Results: The obtained results demonstrated a significant positive association between the RAD51 C/C genotype and endometrial carcinoma, with an adjusted odds ratio (OR) of 3.75 (P < 0.0001). The homozygous C/C genotype was found in 72% of endometrial cancer cases and in 19% of the used controls. The variant 135C allele of RAD51 increased the cancer risk (OR = 1.64 [1.282.10]P < 0.0001). There were no significant differences between the distribution of G135C, Arg188His and Thr241Met genotypes in the subgroups assigned to histological grades. Conclusions: The obtained results indicate that the polymorphism of RAD51, but not of either XRCC2 or XRCC3 genes, may be positively associated with the incidence of endometrial carcinoma in the population of Polish women.

“
“Bladder cancer (BCA) is one of the most common cancers. In 2010 in Poland, 6296 people developed bladder cancer and 3110 people died of it. Immunotherapy with BCG (Bacillus Calmette-Guerin) is by far the most effective adjuvant therapy. Noninfiltrating muscle membrane changes,

that is, stages Ta, Tis and T1 qualify for BCG immunotherapy. BCG immunotherapy comprises series of bladder instillations, containing attenuated strain of Mycobacterium bovis. The effectiveness of immunotherapy in non-invasive bladder www.selleckchem.com/products/gsk126.html cancer is 70% 5-year survival without recurrence of the tumor. The treatment leads to a reduction of the residual tumor mass, but also to the delay and/or prevention of relapse, disease progression and ultimately death. Cytokines, as key mediators of immune response, play an important role in the pathogenesis of bladder cancer, which occurrence is stimulated by the inflammatory process. BCG immunotherapy provokes an intensive immunological response by the increase of cytokine production. Genetic variants determine inter-individual differences in the incidence of this cancer, as well as the response to the therapy. This is evidenced by the presence of differences in genetic variants of cytokines correlated with the varied risk of bladder cancer incidence. It is believed that concentrations of particular cytokines in urine after installation

of BCG may indicate response to the therapy. Increased levels of Th1 cytokines -IFN-gamma, IL-2 and TNF-alpha are correlated DNA Damage inhibitor with longer survival time without recurrence, whereas high levels of Th2 cytokines such as IL-10, predict unsuccessful BCG therapy.”
“Three enzymes with milk-clotting activity have been isolated from the fruiting bodies of Pleurotus ostreatus (Fr.) Kumm) by (NH(4))(2)SO(4) precipitation, ML323 in vitro gel chromatography on Sephadex G75, and ion exchange chromatography on carboxymethylcellulose (CMC). Isoelectric points of the enzymes, as determined by isoelectrofocusing, equaled 4.2, 6.7, and 8.8. Inhibition analysis showed that the enzymes with isoelectric

points of 4.2 and 6.7 belong to the class of metal-dependent proteinases, while the enzyme with the isoelectric point of 8.8 belongs to the serine protease class.”
“Three-component cyclocondensation of methyl 12-aminodehydroabietate with cyclopentadiene and formaldehyde or acetaldehyde under acid catalysis afforded polysubstituted naphthoquinoline derivatives with fused oxetanocyclopentane and cyclopentene fragments. Ozonation of the double bond in the N-trifluoroacetyl cyclopentene derivatives gave the corresponding ozonide.”
“Transforming growth factor beta (TGF-beta) plays a crucial role and takes part in many processes in the human body both in physiology and pathology. This cytokine is involved in angiogenesis, regulates apoptosis and stimulates divisions of cells, such as hepatocytes, lymphocytes or hematopoietic cells.

Efficacy measures included four pain rating scales applied daily using patient diaries, and another two applied at five clinic visits.

Results. On all six scales, DMQ 45/30 mg was significantly superior to placebo, including the primary efficacy analysis, which utilized mixed-effects modeling to test all scores on an 11-point numerical Pain Rating Scale (P < 0.0001). Sensitivity analyses gave consistent results. Efficacy vs placebo was also seen for diary ratings of present pain intensity, and pain interference with sleep and with activities (all P < 0.0001). Among clinic visit assessments, DMQ 45/30 mg demonstrated

https://www.selleckchem.com/products/17-AAG(Geldanamycin).html greater leg pain relief (P = 0.0002) and greater reduction of leg pain intensity (P SHP099 concentration = 0.0286) vs placebo. The efficacy

of DMQ 30/30 mg was numerically less than for 45/30 mg but for most outcomes remained significantly greater vs placebo. Adverse events were mostly mild or moderate and of expected types. Discontinuation for adverse events in the DMQ groups was at least twice as common as placebo.

Conclusions. Throughout a 13-week trial, DMQ was effective, with an acceptable safety profile, for treatment of DPN pain. Other fixed-dose combinations of DMQ should be studied to improve overall tolerability while maintaining significant efficacy.”
“Aim: This paper is a report of a study to describe the attributes of quality nursing narrated by a sample of patients with cancer, their advocates and their nurses.

Background: Quality nursing care is a multifaceted concept which is open to interpretation. Studies show that while

nurses are striving to succeed in providing quality care for their patients and the patients are urging for better nursing care, the complexity in understanding the concept often causes confusion among patients and nurses.

Method: The study was a phenomenological hermeneutical study based on the ideas of the French Philosopher Paul Ricoeur. Twenty-five patients with cancer, six advocates and twenty cancer nurses were recruited in Cyprus by Selleckchem Roscovitine a purposive method. The informants were encouraged to narrate their lived experiences of receiving and providing quality nursing care. A discussion follows whether the findings can be regarded as a theory of quality in cancer care.

Findings: Based on the informants’ narratives the following six attributes of quality nursing care materialized: a) being valued, b) being respected c) being cared for by communicative and supportive nurses, d) being confirmed, e) being cared for religiously and spiritually and f) belonging.

Conclusion: The six attributes can be proposed as a descriptive theory of quality nursing care within the tension between empirical data and pre-understanding. The theory emphasizes the existential needs such as communicated with, being respected, and being cared for which should be considered important when providing nursing care to patients with cancer.

Nanochannels with aspect ratio up to 172 and width down to 44 nm were successfully fabricated on a 4-inch Si wafer with width nonuniformity less than 13.6%. A microfluidic chip integrated with nanometer-sized filters was successfully fabricated by utilizing the present method for geometric-controllable nanoparticle packing. (C) 2012 American Institute of Physics. [doi:10.1063/1.3683164]“
“Objective: To compare the energy expenditure of increased lateral trunk lean walking a suggested method of reducing medial compartment knee joint load compared to normal

walking in a population of older adults with medial knee osteoarthritis (OA).

Method: Participants completed two randomly-presented treadmill walking conditions: 15 mm of normal walking or walking with ten degrees of peak lateral trunk lean. Lateral trunk lean angle was displayed in front of the participant in real-time during treadmill conditions. BAY 80-6946 in vivo Energy expenditure (V02 and METs), heart rate (HR), peak lateral trunk lean angle, knee pain and perceived exertion were measured and differences between

conditions were compared using paired t-tests.

Results: Twelve participants (five males, mean (standard deviation (SD)) age 64.1 (9.4) years, body mass index (BMI) 28.3 (4.9) kg/m(2)) participated. All measures were significantly elevated in the lateral trunk lean condition (P < 0.008), except for knee pain (P = 0.22). Oxygen consumption (V02) was, on average 9.5% (95% Cl 4.2-14.7%) higher, selleck chemical and HR was on average 5.3 beats per minute (95% CI 1.7-9.0 bpm) higher during increased lateral trunk lean walking.

Conclusion: Increased lateral trunk lean walking on a treadmill resulted in significantly higher levels of GSK461364 inhibitor steady-state energy expenditure, HR, and perceived exertion, but no difference in knee pain. While increased lateral trunk lean has been shown to reduce biomechanical measures of joint loading relevant to OA progression, it should be prescribed with caution given the potential increase in energy expenditure experienced when

it is employed. (C) 2013 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.”
“Background: Understanding the relationship between the radii of the medial and lateral femoral condyles in varus and valgus knees is important for aligning the femoral component and for restoring kinematics in total knee arthroplasty. The purpose of this study was to test the hypothesis that the asymmetry between the radii of the medial and lateral femoral condyles in varus and valgus knees with osteoarthritis is small enough to be clinically unimportant.

Methods: A magnetic resonance imaging scan was obtained with use of a biplanar, rotational alignment protocol in a consecutive series of subjects with end-stage osteoarthritis prior to total knee arthroplasty.

4 to 83.5 +/- 24 ml/min (P = 0.028). A significant reduction in GFR was noted in patients with bladder compliance that increased by < 10 cmH(2)O (P = 0.002) and in patients with Pdet decreased by < 10 cmH(2)O after treatment (P = 0.036). All 30 patients with improvement in incontinence grade satisfied with treatment result. Conclusion: This pilot study revealed that repeated detrusor injections of 200 U onabotulinumtoxinA could reduce incontinence grade, increase

bladder capacity, and decrease intravesical pressure but this study did not demonstrate an improvement in GFR learn more over a 24-month period in patients with chronic SCI. Neurourol. Urodynam. 30:1541-1545, 2011. (C) 2011 Wiley Periodicals, Inc.”
“Waste rubber has posed challenging environmental and disposal problems across the world. This study focused on the microbial reclaiming of ground tyre rubber (GTR) by Acidithiobacillus ferrooxidans YT-1 cultured in media with variable Fe2+ concentrations. The Acidithiobacillus ferrooxidans YT-1 strain with the ability of oxidizing sulfur and reclaiming waste rubber was isolated and identified. Toxicity tests of different rubber and additives in tyre SB525334 datasheet rubber compounds to microorganisms was quantitatively investigated. After desulfurization, there were many small colonies on the surface of the desulfurizated

GTR (DGTR), due to surface degradation by A. ferrooxidans YT-1. The amount of small colonies increased and sulfur content decreased with the increase of Fe2+ concentrations in the media, implying that Fe2+ concentration had a great influence on the degradation ability of A. ferrooxidans YT-1. A medium with a high Fe2+ concentration was good for growth of A. ferrooxidans YT-1. Compared with styrene butadiene rubber (SBR)/GTR blends, the tensile strength and elongation at the break of the SBR/DGTR blends were significantly improved. The scanning electron microscope (SEM) photographs of the fracture surface further indicated a good coherency between DGTR and the SBR matrix. These results revealed that A. ferrooxidans YT-1 cultured in a

medium with a high Fe2+ concentration could improve the reclaiming efficiency of waste rubber.”
“We compared systolic (SBP) and diastolic blood pressure (DBP), mean arterial pressure (MAP) and pulse pressure (PP) as independent selleck products predictors of cardiovascular disease (CVD), total and CVD mortality among an Iranian population. The study conducted among 5991 subjects aged >= 30 years without baseline CVD and antihypertensive medication. The mean of two measurements of SBP and DBP, in sitting position, was considered the subject’s blood pressure. During a median follow-up of 8.7 years, 346 CVD and 157 deaths, 63 attributed to CVD, occurred. Hazard ratios (HRs) of each outcome were calculated for a one standard deviation (SD) increase in each blood pressure (BP) measures. In multivariate models, all BP measures were associated with increased risk of CVD regardless of age.

5-0.6 eV conventional optimum. The cells have been modeled using fundamental physical parameters from the InGaAs and InGaAsP material system which accurately reproduce reported device performance and allow a comparison to theoretical limits. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3488903]“
“The Tibagi River, located in southern Brazil, is associated with a significant degree of environmental heterogeneity, along its 550 km extension. There is concern about the integrity of this river’s ecosystem, as human interference has been increasing. Aegiphila

sellowiana (Lamiaceae) is an important pioneer tree species, commonly AZD8931 order found near rivers; the fruit is consumed by avifauna. We studied this species along three ecological gradients, comprising the upper, middle, and lower regions of the Tibagi River basin. The genetic structure of nine subpopulations of A. sellowiana distributed along these gradients was investigated using RAPDs. Moderate levels of gene diversity (ranging from 0.091 to 0.132) OICR-9429 cell line were identified, inferred by a traditional approach and a Bayesian

model-based method. The F-statistic, G(ST) parameters and molecular variance analysis showed high genetic differentiation among the three regions (39.5 to 50.26%). Analysis of molecular variance revealed high levels of genetic variation between populations (50.26%), while lower values of genetic variation (ranging from 9.56 to 16.35%) were seen between subpopulations within the upper, middle, and lower regions of the Tibagi River basin. The validity of these results was confirmed by Caspase 抑制剂 principal coordinate analysis. Linear regression analysis showed significant correlations (r = 0.621, P = 0.0001) between the genetic and geographical distances. The differences observed in genetic variation

between regions are probably due to habitat fragmentation; for conservation purposes, we recommend that at least one subpopulation from each region of the Tibagi River should be maintained.”
“In this study, we detected the expression of phosphylated ERK1/2 in human salivary adenoid cystic carcinoma (SACC) by immunohistochemical method, the effect of various concentrations of PD98059 on the growth of ACC-M cells (a cell line of human adenoid cystic carcinoma of the salivary glands) by MTT assay, and the effect of PD98059 on the lung metastasis of inoculated ACC-M cells in nude mice. The results showed that the phosphylated ERK1/2 was overexpressed in SACC, the ACC-M cell line proliferation was inhibited by PD98059, and the lung metastasis level was reduced by PD98059, indicating that ERK may be a key molecule in targeted therapy of adenoid cystic carcinoma. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010; 109: 117-123)”
“A common assumption in both experimental measurements and device modeling of bulk heterojunction (BHJ) organic solar cells is that parasitic resistances are ideal.

In the first we use the seed-specific ABI3 promoter to drive the TPS1 cDNA during embryo development, resulting in rescue of the embryo-lethal tps1 phenotype. Lack of expression from the ABI3::TPS1 transgene

in post-germinative tps1 seedlings results in severe growth arrest, accumulation of soluble sugars and starch and leads to an increase in expression of genes related to ABA signalling. In the second approach we use TILLING (targeted induced local lesions in genomes) to generate three weaker, non-embryo-lethal, Selumetinib purchase alleles (tps1-11, tps1-12 and tps1-13) and use these to demonstrate that the TPS1 protein plays a key role in modulating trehalose 6-phosphate (T6P) levels in vegetative tissues of Arabidopsis. All three weaker alleles give a consistent phenotype of slow growth and delayed flowering. Germination of tps1-11, tps1-12 and tps1-13 is hypersensitive to ABA with the degree of hypersensitivity correlating with the decrease in T6P levels in the different alleles. Stomatal pore aperture is regulated by ABA, and this was found to be affected in tps1-12. Our results show that the TPS1 gene product plays an essential role in regulating the growth of vegetative as well as embryogenic tissue in a mechanism involving ABA and sugar metabolism.”
“Oscillometric devices are being widely used for selleck compound ambulatory, home and office blood pressure ( BP) measurement. However, even successfully JQ-EZ-05 cost validated oscillometric

devices fail to provide accurate measurements in some patients. This study investigated the prevalence, the reproducibility and the characteristics of the phenomenon of unreliable oscillometric BP (UOBP) measurement. A total of 5070 BP measurements were obtained simultaneously (Y connector) using a professional oscillometric device (BpTRU) and a mercury sphygmomanometer in 755 patients (1706 visits). UOBP readings were defined as those with >10 mm Hg difference (systolic or diastolic) between the two

methods. UOBP was found in 15% of systolic and 6.4% of diastolic BP measurements. In all, 18% of the participants had UOBP in their first but not their second visit, or the reverse. However, 49% of these participants had at least one more UOBP visit after their second visit within the study database. Patients with persistent UOBP were more likely to be female and had lower arm circumference. The systolic BP discrepancy between the two methods was associated with pulse pressure (r = 0.41) and inversely with diastolic BP (r = 0.40) and arm circumference (r = 0.30), whereas the diastolic discrepancy with diastolic BP (r = 0.61) and inversely with pulse pressure (r = 0.32). There was a consistent significant trend for larger systolic BP discrepancy and smaller diastolic from the lower to the higher pulse pressure quintile (P<0.0001). A decreasing arm circumference was a significant predictor of persistent UOBP.

This study confirms that the validity and reliability of OLQ-13 may differ substantially

in different populations.”
“Modelling the behaviour of extinct hominins is essential in order to devise useful hypotheses of our species’ evolutionary origins for testing in the palaeontological and archaeological records. One approach is to model the last common ancestor (LCA) of living apes and humans, based on current ethological and ecological knowledge of our closest living relations. Such referential modelling is based on rigorous, ongoing field studies of the chimpanzee (Pan troglodytes) and the bonobo (Pan paniscus). This paper reviews recent findings from nature, focusing on those SB-715992 with direct implications for hominin evolution, e.g. apes, using elementary technology to access basic resources such as food and water, or sheltering in caves or bathing as thermoregulatory adaptations. I give preference to studies Selisistat manufacturer that directly address key issues, such as whether stone artefacts are detectible before the Oldowan, based on the percussive technology of hammer and anvil use by living apes. Detailed comparative studies of chimpanzees living in varied habitats,

from rainforest to savannah, reveal that some behavioural patterns are universal (e.g. shelter construction), while others show marked (e.g. extractive foraging) or nuanced (e.g. courtship) cross-populational variation. These findings allow us to distinguish between retained, primitive traits of the LCA versus derived ones in the human lineage.”
“The objective of this study was

to assess cognition and behavior in children (4-16 years; n = 103) with partial-onset seizures using the Leiter-R International Performance Scale and Achenbach Child Behavior Checklist. The study was a multicenter, open-label, noncomparative 48-week extension study (NCT00152516) of adjunctive this website levetiracetam (20-100 mg/kg/d, mean 50.2 mg/kg/d). Improvement from baseline in Leiter-R Memory Screen composite score at weeks 24 and 48 (mean [SD] change, +4.8 [12.6] and +4.5 [15.3]) was similar to changes observed with levetiracetam and placebo in a prior study. Child Behavior Checklist Syndrome scores improved from baseline at weeks 24 and 48 (total problems mean [SD] change, -9.3 [22.2] and -10.4 [23.4]). Adjunctive levetiracetam was well tolerated (most frequently reported central nervous system-related treatment-emergent adverse events: headache [24.3%], aggression [7.8%], irritability [7.8%]). Of the patients, 4.9% discontinued because of treatment-emergent adverse events. Levetiracetam provided good and sustained seizure control (median percentage reduction from baseline in partial-onset seizure frequency/wk during maintenance: 86.4%); 24.7% of patients had continuous seizure freedom from all seizure types for >= 40 weeks.

These results selleck compound could enhance our understanding of the functions of germinal centers.”
“Based on an idealized 1D model we demonstrate that electrons oscillating in a Penning trap may get bunched, at the resonant frequency of the active medium. During multiple round trips in the trap, the bunched electrons gain energy and, therefore, they may escape the trap forming a low energy optical injector. (C) 2011 American Institute of Physics. [doi:10.1063/1.3559761]“
“Background: QRS width and echocardiography-derived indices are limited

predictors of response to resynchronization therapy. We applied digital palpography, using vibration resonance imaging, to investigate the effects of right ventricular pacing and left ventricular ejection fraction Etomoxir research buy (LVEF) on mechanical and electrical dyssynchrony.

Methods: Forty-nine subjects were examined: 24 normal controls, 18 subjects with right ventricular apical pacing (12 with reduced LVEF), and seven subjects with reduced LVEF and narrow QRS. Digital measurement of QRS width was performed. Electric dyssynchrony index (EDI) was measured as the time interval between peak R-waves of the same QRS complex of simultaneously recorded standard limb electrocardiograms,

L1 and L2. A matrix of 6 x 6 vibration recording transducers was applied to chest. The interval between the onset of Q-wave and the peak of amplitude vibration for each transducer was measured, and a three-dimensional map for the whole matrix of transducers was generated. Median values (QE1) were measured. Mechanical vibration systolic dyssynchrony index (VSDI) for each subject was determined as the standard deviation of the difference between the median value and each transducer interval.

Results: EDI was larger in subjects with right ventricular pacing. Mechanical dyssynchrony indices were larger with pacing and reduced LVEF. EDI correlated with QRS width (r(2) = 0.7), with VSDI (r(2) = 0.42), and with QE1 (r(2) = 0.74). QRS width correlated with QE1 (r(2) = 0.75).

Conclusions: Digital chest palpography can determine dyssynchrony indices

that are larger in subjects with right ventricular pacing and reduced LVEF and AL3818 correlate with parameters of electrical dyssynchrony. (PACE 2011; 34: 875-883)”
“The functioning of living cells requires efficient and selective transport of materials into and out of the cell, and between different cellular compartments. Much of this transport occurs through nano-scale channels that do not require large scale molecular re-arrangements (such as transition from a ‘closed’ to an ‘open’ state) and do not require a direct input of metabolic energy during transport. Nevertheless, these ‘always open’ channels are highly selective and pass only their cognate molecules, while efficiently excluding all others; indeed, these channels can efficiently transport specific molecules even in the presence of a vast excess of non-specific molecules.