Cyclable Variable Path Length Multilevel Structures for Lossless Ion Manipulations (SLIM) Platform for Enhanced Ion Mobility Separations.

Ion mobility-mass spectrometry (IMS-MS) is used to analyze complex samples and provide structural information on unknown compounds. As the complexity of samples increases, there is a need to improve the resolution of IMS-MS instruments to increase the rate of molecular identification. This work evaluated a cyclable and variable path length (and hence resolving power) multilevel Structures for Lossless Ion Manipulations (SLIM) platform to achieve a higher resolving power than what was previously possible. This new multilevel SLIM platform has eight separation levels connected by ion escalators, yielding a total path length of ∼88 m (∼11 m per level). Our new multilevel SLIM can also be operated in an "ion cycling" mode by utilizing a set of return ion escalators that transport ions from the eighth level back to the first, allowing even extendable path lengths (and higher IMS resolution). The platform has been improved to enhance ion transmission and IMS separation quality by reducing the spacing between SLIM boards. The board thickness was reduced to minimize the ions' escalator residence time. Compared to the previous generation, the new multilevel SLIM demonstrated better transmission for a set of phosphazene ions, especially for the low-mobility ions. For example, the transmission of m/z 2834 ions was improved by a factor of ∼3 in the new multilevel SLIM. The new multilevel SLIM achieved 49% better resolving powers for GRGDS1+ ions in 4 levels than our previous 4-level SLIM. The collision cross-section-based resolving power of the SLIM platform was tested using a pair of reverse sequence peptides (SDGRG1+, GRGDS1+). We achieved 1100 resolving power using 88 m of path length (i.e., 8 levels) and 1400 following an additional pass through the eight levels. Further evaluation of the multilevel SLIM demonstrated enhanced separation for positively and negatively charged brain total lipid extract samples. The new multilevel SLIM enables a tunable high resolving power for a wide range of ion mobilities and improved transmission for low-mobility ions.

Quantifying terpenes in tomato leaf extracts from different species using gas chromatography-mass spectrometry (GC-MS).

Terpenes play a vital role in plant defense; tomato plants produce a diverse range of terpenes within specialized glandular trichomes, influencing interactions with herbivores, predators, and pollinators. This study employed two distinct methods, namely leaf dip and maceration, to extract trichomes from tomato leaves. Terpene quantification was carried out using Gas Chromatography-Mass Spectrometry (GC-MS). The leaf dip method proved effective in selectively targeting trichome content, revealing unique extraction patterns compared to maceration. The GC-MS method demonstrated high linearity, accuracy, sensitivity, and low limits of detection and quantification. Application of the method to different tomato species (Solanum pennellii, Solanum pimpinellifolium, Solanum galapagense, Solanum habrochaites, and Solanum lycopersicum) identified significant variation in terpene content among these species, highlighting the potential of specific accessions for breeding programs. Notably, the terpene α-zingiberene, known for its repellency against whiteflies, was found in high quantities (211.90-9155.13 µg g-1) in Solanum habrochaites accession PI209978. These findings provide valuable insights into terpenoid diversity for plant defense mechanisms, guiding future research on developing pest-resistant tomato cultivars. Additionally, the study underscores the broader applications of terpenes in agriculture.

The effect of Pilates exercise during pregnancy on delivery outcomes: a systematic review and meta-analysis.

A systematic review and meta-analysis were conducted to investigate the effectiveness of the Pilates exercise program during pregnancy on different delivery outcomes. Various databases were searched from inception until November 2022. The included studies compared Pilates exercise to routine antenatal care in pregnant women. The primary outcomes assessed were vaginal and cesarean delivery rates, as well as labor duration. Secondary outcomes included episiotomy incidence, Apgar scores, and epidural analgesia. Seven studies met the inclusion criteria, involving a total of 1,003 patients. Results indicated a significant increase in the vaginal delivery rate among the Pilates exercise group compared to the control group (p < .001). Moreover, the Pilates exercise group exhibited significantly reduced rates of cesarean delivery and shorter labor duration. Pilates exercise was associated with a significant decline in the incidence of episiotomy and the number of women requiring epidural analgesia during delivery (p < .001 & p = .008). In addition, Apgar scores at one and five minutes were significantly higher in the Pilates exercise group compared to the control group (p < .001). In conclusion, Pilates exercise during pregnancy has a positive effect on maternal outcomes and Apgar scores. However, more trials are needed to confirm these findings.

Impaired Tertiary Dentin Secretion after Shallow Injury in Tgfbr2-Deficient Dental Pulp Cells Is Rescued by Extended CGRP Signaling.

The transforming growth factor ß (TGFß) superfamily is a master regulator of development, adult homeostasis, and wound repair. Dysregulated TGFß signaling can lead to cancer, fibrosis, and musculoskeletal malformations. We previously demonstrated that TGFß receptor 2 (Tgfbr2) signaling regulates odontoblast differentiation, dentin mineralization, root elongation, and sensory innervation during tooth development. Sensory innervation also modulates the homeostasis and repair response in adult teeth. We hypothesized that Tgfbr2 regulates the neuro-pulpal responses to dentin injury. To test this, we performed a shallow dentin injury with a timed deletion of Tgfbr2 in the dental pulp mesenchyme of mice and analyzed the levels of tertiary dentin and calcitonin gene-related peptide (CGRP) axon sprouting. Microcomputed tomography imaging and histology indicated lower dentin volume in Tgfbr2cko M1s compared to WT M1s 21 days post-injury, but the volume was comparable by day 56. Immunofluorescent imaging of peptidergic afferents demonstrated that the duration of axon sprouting was longer in injured Tgfbr2cko compared to WT M1s. Thus, CGRP+ sensory afferents may provide Tgfbr2-deficient odontoblasts with compensatory signals for healing. Harnessing these neuro-pulpal signals has the potential to guide the development of treatments for enhanced dental healing and to help patients with TGFß-related diseases.

Sas20 is a highly flexible starch-binding protein in the Ruminococcus bromii cell-surface amylosome.

Ruminococcus bromii is a keystone species in the human gut that has the rare ability to degrade dietary resistant starch (RS). This bacterium secretes a suite of starch-active proteins that work together within larger complexes called amylosomes that allow R. bromii to bind and degrade RS. Starch adherence system protein 20 (Sas20) is one of the more abundant proteins assembled within amylosomes, but little could be predicted about its molecular features based on amino acid sequence. Here, we performed a structure-function analysis of Sas20 and determined that it features two discrete starch-binding domains separated by a flexible linker. We show that Sas20 domain 1 contains an N-terminal ß-sandwich followed by a cluster of α-helices, and the nonreducing end of maltooligosaccharides can be captured between these structural features. Furthermore, the crystal structure of a close homolog of Sas20 domain 2 revealed a unique bilobed starch-binding groove that targets the helical α1,4-linked glycan chains found in amorphous regions of amylopectin and crystalline regions of amylose. Affinity PAGE and isothermal titration calorimetry demonstrated that both domains bind maltoheptaose and soluble starch with relatively high affinity (Kd ≤ 20 µM) but exhibit limited or no binding to cyclodextrins. Finally, small-angle X-ray scattering analysis of the individual and combined domains support that these structures are highly flexible, which may allow the protein to adopt conformations that enhance its starch-targeting efficiency. Taken together, we conclude that Sas20 binds distinct features within the starch granule, facilitating the ability of R. bromii to hydrolyze dietary RS.

A pilot study to compare propranolol and misoprostol versus misoprostol and placebo for induction of labor in primigravidae; a randomized, single-blinded, placebo-controlled trial.

BACKGROUND: The Induction of labor is the most common obstetric procedure in daily practice. Introducing propranolol as a new drug to augment the action of prostaglandins will help in the induction process and decrease CS rates. Several researchers have used propranolol in the augmentation of labor. AIM: This pilot study compares propranolol and misoprostol versus misoprostol alone for labor induction in primigravids. METHODS: This is a Randomized clinical trial, single-blinded, placebo-controlled trial at Ain Shams University Maternity hospital. This study included 128 pregnant full-term primigravid women candidates for labor induction, randomized into two groups. All candidates underwent labor induction with 25 µg of vaginal misoprostol. Group I received 20 mg of oral propranolol tablets, while group II received sugary pills as a placebo. Candidates who responded successfully to induction were assessed for possible augmentation of labor by amniotomy or oxytocin infusion. The Primary outcome was induction to delivery interval, while the secondary outcomes were the duration of the latent phase, mode of delivery, and APGAR score of the neonate. RESULTS: The induction-delivery time was (11.8 ± 8.1 h. vs. 12.6 ± 8.9 h., P value = 0.027) and the duration of the latent phase of labor (7.9 ± 5.6 h. vs. 9.2 ± 6.03 h., P value = 0.017) were significantly shorter in the group of misoprostol and propranolol compared to the group of misoprostol and placebo. There was no statistically significant difference between both groups' mode of delivery, indications for cesarean section, misoprostol, and oxytocin doses, or neonatal outcome. (P value > 0.05). CONCLUSION: Propranolol, when used with misoprostol for induction of labor, results in augmentation of action of misoprostol and a significantly shorter induction-delivery interval. TRIAL REGISTRATION: We retrospectively registered this trial in clinicaltrial.gov on 01/09/2020 (NCT04533841). https://clinicaltrials.gov/ct2/show/NCT04533841.

A comparative study to evaluate microstrain of low-profile attachment associated with and without bar connection in implant assisted mandibular overdenture (in vitro study).

BACKGROUND: The aim of this study was to compare the microstrain transmitted to peri-implant tissues of implant-assisted mandibular overdentures using two different low-profile attachment designs; OT- Equator attachment with and without bar attachment. MATERIALS AND METHODS: A completely edentulous epoxy resin mandibular model was used, in which two parallel dental implants were inserted at the canine region bilaterally and one in the middle. Sixteen identical complete edentulous mandibular overdentures were fabricated following conventional, standardized techniques and were divided equally between two groups according to the design and placement of the OT-Equator. Group A implants were kept solitary with an OT-Equator attachment, while group B implants were kept splinted with a bar associated with two mini-OT-Equator attachments in between. Sixteen identical mandibular complete overdentures were constructed, to which attachments were picked up. The difference in stress distribution was measured using strain gauges and compared between the two studied groups. A vertical load of 100 N using the universal testing machine was applied unilaterally on the left mesial fossae of the mandibular first molar and bilaterally on the bar attached to the mandibular premolar molar region of the overdentures. Statistical analysis was conducted using IBM SPSS version 28. Normality was checked by using the Shapiro-Wilk test and normality plots. The Mann-Whitney U test was then used to analogize the groups. RESULTS: There was a statistically significant difference between groups A and B upon application of vertical unilateral and bilateral loadings of 100 N, with mean microstrain values of P 0.05. Group A (OT-Equator attachment) showed lower strain values than Group B (OT-Equator bar attachment) upon application of vertical, unilateral, and bilateral loadings of 100 N. CONCLUSIONS: Implant-assisted mandibular overdenture with a solitary attachment is associated with lower microstrain values around the implants after application of unilateral and bilateral vertical loadings of 100 N.

The possible protective role of pimpinella anisum oil versus selenium on aspartame induced changes in rat cerebellar cortex: histological, immunohistochemical and electron microscopic study.

Aspartame (ASP) is an artificial sweeter. Chronic use of ASP has a harmful effect on cerebellar cortex. Anisum oil and selenium (SE) are antioxidant substances. Therefore, the present study was performed to study the possible protective role of anisum oil versus selenium on aspartame-induced changes in rat cerebellar cortex. Rats were divided into four main groups. Group I (Control group). Group II received 250 mg/kg/day aspartame once daily for 2 months. Group III received 0.5 ml/kg/day anisum 2 h before aspartame administration. Group IV received 0.5 mg/kg/day selenium 2 h before aspartame administration. The administration of Asp for 2 months (group II) resulted in cerebellar histopathological changes in the form of deformed Purkinje and granule cells. Ultrastructurally, Purkinje cells had irregular nuclei, dilated cisternae of rough endoplasmic reticulum, dilated saccules of Golgi apparatus, mitochondria with destroyed cristae. In addition, granule cells appeared shrunken with irregular nuclei. Aspartame and anisum oil treated group (group III) showed partial improvement. Examination of ASP and SE treated group (group IV) showed that cerebellar cortex was nearly similar to control. In conclusion, Anisum oil and selenium could protect against ASP-induced cerebellar damage. The protective effect of selenium is better than anisum oil.

Promising minimally invasive treatment modalities for symptomatic temporomandibular joint disc displacement with reduction: a randomized controlled clinical trial.

BACKGROUND: Pain and clicking are the primary complaints in patients suffering from temporomandibular joint disc displacement with reduction (DDwR), negatively affecting the patients' quality of life, making the treatment essential. This prospective randomized controlled trial (RCT) was conducted to evaluate the effectiveness of botulinum toxin type-A (BTX-A) and low level laser therapy (LLLT) in comparison to anterior repositioning appliance (ARA) for the treatment of DDwR. METHODS: A total of 27 patients were randomly allocated to 3 groups; ARA (control group), BTX-A, and LLLT; with 9 patients each. All patients were evaluated before and 3 months after the treatment using a visual analogue scale (VAS) and magnetic resonance imaging (MRI). RESULTS: At 3 months follow-up, all groups showed a significant reduction in pain assessed by VAS (P = 0.007). Measured on MRI, there was a significant improvement in disc position and joint space index (JSI) in BTX-A group (P < 0.001, P = 0.011) and LLLT group (P = 0.002, P = 0.017) in comparison to the control group (P = 0.087, P = 0.066) respectively. As for time of recovery, a statistically significant difference was observed in BTX-A group (P < 0.001) and LLLT (P < 0.001) group in comparison to ARA group, which showed the most prolonged duration for reduction of DDwR symptoms. CONCLUSION: We concluded that BTX-A and LLLT could be considered effective alternative treatment modalities to ARA regarding reducing joint pain, clicking, and improving disc position in patients with symptomatic DDwR. TRIAL REGISTRATION: This prospective double-blinded RCT has been registered at ClinicalTrials.gov with identification number: NCT05194488, 18/1/2022.

Thermophilic Degradation of Hemicellulose, a Critical Feedstock in the Production of Bioenergy and Other Value-Added Products.

Renewable fuels have gained importance as the world moves toward diversifying its energy portfolio. A critical step in the biomass-to-bioenergy initiative is deconstruction of plant cell wall polysaccharides to their unit sugars for subsequent fermentation to fuels. To acquire carbon and energy for their metabolic processes, diverse microorganisms have evolved genes encoding enzymes that depolymerize polysaccharides to their carbon/energy-rich building blocks. The microbial enzymes mostly target the energy present in cellulose, hemicellulose, and pectin, three major forms of energy storage in plants. In the effort to develop bioenergy as an alternative to fossil fuel, a common strategy is to harness microbial enzymes to hydrolyze cellulose to glucose for fermentation to fuels. However, the conversion of plant biomass to renewable fuels will require both cellulose and hemicellulose, the two largest components of the plant cell wall, as feedstock to improve economic feasibility. Here, we explore the enzymes and strategies evolved by two well-studied bacteria to depolymerize the hemicelluloses xylan/arabinoxylan and mannan. The sets of enzymes, in addition to their applications in biofuels and value-added chemical production, have utility in animal feed enzymes, a rapidly developing industry with potential to minimize adverse impacts of animal agriculture on the environment.

Early recovery patterns of olfactory disorders in COVID-19 patients; a clinical cohort study.

INTRODUCTION: A rapidly evolving evidence suggests that smell dysfunction is a common symptom in COVID-19 infection with paucity of data on its duration and recovery rate. OBJECTIVES: Delineate the different patterns of olfactory disorders recovery in patients with COVID-19. METHODS: This cross-sectional cohort study included 96 patients with olfactory complaint confirmed to be COVID-19 positive with recent onset of anosmia. All patients were inquired for smell recovery patterns using self-assessment questionnaires. RESULTS: Ninety six patients completed the study with mean age 34.26 ±â€¯11.91 years. Most patients had sudden anosmia 83%. Loss of smell was accompanied by nonspecific inflammatory symptoms as low-grade fever (17%) and generalized body ache (25%). Nasal symptoms were reported by 33% of patients. Some patients reported comorbidities as D.M (16%), hypertension (8%) or associated allergic rhinitis (25%), different patterns of olfactory recovery showed 32 patients experiencing full recovery (33.3%) while, 40 patients showed partial recovery (41.7%) after a mean of 11 days while 24 patients (25%) showed no recovery within one month from onset of anosmia. CONCLUSION: The sudden olfactory dysfunction is a common symptom in patients with COVID-19. Hyposmia patients recover more rapidly than anosmic ones while the middle age group carried the best prognosis in olfactory recovery. Females possess better potentiality in regaining smell after recovery and the association of comorbidities worsen the recovery rate of olfactory dysfunction in patients with COVID19. LEVEL OF EVIDENCE: Level 2b a cross-sectional cohort study.

Dysplastic urothelial changes accompany empagliflozin administration in urinary bladder of experimental diabetes.

Empagliflozin (EMPA) is a promising novel antidiabetic drug; however, doubts have been raised regarding its use and the increased risk of urinary bladder carcinoma. In this study, we evaluated urothelium expression of cytokeratins (CKs) and Ki-67 proliferative activity in the urinary bladder of diabetic (DM + EMPA) and non-diabetic rats after EMPA administration. By routine histology, dysplastic changes were detected in the urothelium of diabetic as well as non-diabetic animals after EMPA administration. Moreover, the expression of CK-7 and CK-8 was significantly decreased (P < .05) while that of CK-20 as well as Ki-67 was significantly increased (P < .05) in EMPA per se and DM + EMPA urothelium groups compared to that of control and diabetics. The dysplastic changes together with the increased proliferative activity in urothelium after EMPA administration provide a cellular evidence that supports the former clinical concerns.

Structures of benzonitrile dimer radical cation and the protonated dimer: Observation of hydronium ion core solvated by benzonitrile molecules.

The recent discovery of benzonitrile (C6H5CN), one of the simplest nitrogen-bearing polar aromatic molecules, in the interstellar medium motivates structural characterization of the benzonitrile-containing molecular ions as potential precursors for nitrogen-containing complex organics in space. Herein, we present mass-selected ion mobility measurements combined with density functional theory (DFT) calculations to reveal, for the first time, the structures of the benzonitrile dimer radical cation, the protonated dimer, and the protonated hydrated small clusters in the gas phase. The measured collision cross sections of the investigated ions in helium are in excellent agreement with the calculated values of the lowest energy DFT structures. Unlike the dimer radical cations of nonpolar aromatic molecules which adopt parallel sandwich configurations, the (C6H5CN)2 ·+ displays a symmetrically planar geometry with a double hydrogen bond formed between the nitrogen and hydrogen atoms. The protonated dimer has the structure of a proton-bound dimer (C6H5CNH+NCC6H5) where the bridging proton connects the nitrogen atoms in the two benzonitrile molecules resulting in a calculated collision cross section of 101.1 Å2 in excellent agreement with the measured value of 103.3 Å2. The structure of the hydrated protonated trimer consists of a hydronium ion core solvated by three benzonitrile molecules. By locating the proton on the lower proton affinity water molecule, the resulting hydronium ion can be fully solvated by forming three ionic hydrogen bonds with the benzonitrile molecules. These unique structural motifs could be useful for the molecular design and recognition involving charged aromatic systems and also for the search of nitrogen-containing complex organics in space.

The Potential for Ion Mobility in Pharmaceutical and Clinical Analyses.

The pharmaceutical and clinical industries are imperative for the maintenance of global health and welfare and require accurate, reproducible, and high throughput analyses. Technological advancements, such as the development and implementation of liquid chromatography-tandem mass spectrometry (LC-MS), have allowed for improvements in these areas, however there is still room for development. One way in which current analyses may be improved is by the implementation of ion mobility technology. Ion mobility has the capability to produce much more comprehensive data sets, by providing separation of isomers, as well as improving throughput, with separations being performed as fast as 60 ms. Here we will discuss the potential for ion mobility to assist in the two specific areas of glycosylation monitoring of biological drugs, and vitamin D analysis, as representatives of ion mobility's potential in both the pharmaceutical and clinical industries, respectively, as well as the current hurdles of ion mobility adoption in both fields.

Correlation between testicular mast cell count and spermatogenic epithelium in non-obstructive azoospermia.

Although there is emerging evidence that mast cells are involved in infertility, their exact role has not been elucidated clearly. Here we carried out a retrospective case-control study to find out whether there is a correlation between mast cell (MC) count and proliferation (Ki67 index) of the spermatogenic epithelium as well as of the Sertoli cells (vimentin-positive) in non-obstructive azoospermia (NOA). We assessed MCs, Ki67 and vimentin expression in Sertoli cells in testicular biopsies of germ cell aplasia (GCA, n = 14) and maturation arrest (MA, n = 14) vs. normal spermatogenesis (n = 14) cases. There was a significant decrease in the spermatogonial Ki67 index (1.25 ± 0.91, 4.21 ± 1.81 vs. 39.57 ± 3.92) and Johnsen score (2.48 ± 0.65, 4.89 ± 1.05 vs. 9.75 ± 0.30) as well as a significant increase (P < 0.001) in MC count (29.00 ± 4.11, 7.57 ± 1.95 vs. 3.00 ± 1.30) in seminiferous tubules of infertile cases with GCA and MA vs. controls. On the other hand, the percentage of vimentin-expressing Sertoli cells was significantly decreased (P < 0.001) in biopsies of cases with MA (35.50 ± 15.62) compared to those of cases with GCA and controls (72.64 ± 10.67 and 98.57 ± 1.45 respectively). Additionally, a significant negative correlation was detected between MC count and Ki67 index as well as Johnsen score in the MA group which became more significant in the GCA group. The significant increase in MC count in the GCA group and to a lesser extent in the MA group indicates their possible role in NOA particularly at the spermatogonial proliferation level and this is supported by the significant negative correlation with the Ki67 index.

Characterization of applied fields for ion mobility separations in traveling wave based structures for lossless ion manipulations (SLIM).

Ion mobility (IM) is rapidly gaining attention for the separation and analysis of biomolecules due to the ability to distinguish the shapes of ions. However, conventional constant electric field drift tube IM separations have limited resolving power, constrained by practical limitations on the path length and maximum applied voltage. The implementation of traveling waves (TW) in IM removes the latter limitation, allowing higher resolution to be achieved using extended path lengths. Both of these can be readily obtained in structures for lossless ion manipulations (SLIM), which are fabricated from arrays of electrodes patterned on two parallel surfaces where potentials are applied to generate appropriate electric fields between the surfaces. Here we have investigated the relationship between the primary SLIM variables, such as electrode dimensions, inter-surface gap, and the applied TW voltages, that directly impact the fields experienced by ions. Ion trajectory simulations and theoretical calculations have been utilized to understand the dependence of SLIM geometry and effective electric fields on IM resolution. The variables explored impact both ion confinement and the observed IM resolution using SLIM modules.

Ion Elevators and Escalators in Multilevel Structures for Lossless Ion Manipulations.

We describe two approaches based upon ion "elevator" and "escalator" components that allow moving ions to different levels in structures for lossless ion manipulations (SLIM). Guided by ion motion simulations, we designed elevator and escalator components based upon ion current measurements providing essentially lossless transmission in multilevel designs. The ion elevator design allowed ions to efficiently bridge a 4 mm gap between levels. The component was integrated in a SLIM and coupled to a QTOF mass spectrometer using an ion funnel interface to evaluate the m/z range transmitted as compared to transmission within a level (e.g., in a linear section). The analysis of singly charged ions of m/z 600-2700 produced similar mass spectra for both elevator and straight (linear motion) components. In the ion escalator design, traveling waves (TW) were utilized to transport ions efficiently between two SLIM levels. Ion current measurements and ion mobility (IM) spectrometry analysis illustrated that ions can be transported between TW-SLIM levels with no significant loss of either ions or IM resolution. These developments provide a path for the development of multilevel designs providing, e.g., much longer IM path lengths, more compact designs, and the implementation of much more complex SLIM devices in which, e.g., different levels may operate at different temperatures or with different gases.

Serpentine Ultralong Path with Extended Routing (SUPER) High Resolution Traveling Wave Ion Mobility-MS using Structures for Lossless Ion Manipulations.

Ion mobility (IM) separations have a broad range of analytical applications, but insufficient resolution often limits their utility. Here, we report on ion mobility separations in a structures for lossless ion manipulations (SLIM) serpentine ultralong path with extended routing (SUPER) traveling wave (TW) ion mobility (IM) module in conjunction with mass spectrometry (MS). Ions were confined in the SLIM by rf fields in conjunction with a DC guard bias, enabling essentially lossless TW transmission over greatly extended paths. The extended routing utilized multiple passes (e.g., ∼1094 m over 81 passes through the 13.5 m serpentine path) and was facilitated by the introduction of a lossless ion switch that allowed ions to be directed to either the MS detector or for another pass through the serpentine separation region, allowing theoretically unlimited IM path lengths. The multipass SUPER IM-MS provided resolution approximately proportional to the square root of the number of passes (or total path length). More than 30-fold higher IM resolution (∼340 vs ∼10) for Agilent tuning mix m/z 622 and 922 ions was achieved for 40 passes compared to commercially available drift tube IM and other TWIM-based platforms. An initial evaluation of the isomeric sugars lacto-N-hexaose and lacto-N-neohexaose showed the isomeric structures to be baseline resolved, and a new conformational feature for lacto-N-neohexaose was revealed after 9 passes. The new SLIM SUPER high resolution TWIM platform has broad utility in conjunction with MS and is expected to enable a broad range of previously challenging or intractable separations.

Compression Ratio Ion Mobility Programming (CRIMP) Accumulation and Compression of Billions of Ions for Ion Mobility-Mass Spectrometry Using Traveling Waves in Structures for Lossless Ion Manipulations (SLIM).

We report on the implementation of a traveling wave (TW) based compression ratio ion mobility programming (CRIMP) approach within structures for lossless ion manipulations (SLIM) that enables both greatly enlarged trapped ion charge capacities and also efficient ion population compression for use in ion mobility (IM) separations. Ion accumulation is conducted in a SLIM serpentine ultralong path with extended routing (SUPER) region after which CRIMP compression allows the large ion populations to be "squeezed". The SLIM SUPER IM module has two regions, one operating with conventional traveling waves (i.e., traveling trap; TT region) and the second having an intermittently pausing or "stuttering" TW (i.e., stuttering trap; ST region). When a stationary voltage profile was used in the ST region, ions are blocked at the TT-ST interface and accumulated in the TT region and then can be released by resuming a conventional TW in the ST region. The population can also be compressed using CRIMP by the repetitive merging of ions distributed over multiple TW bins in the TT region into a single TW bin in the ST region. Ion accumulation followed by CRIMP compression provides the basis for the use of larger ion populations for IM separations. We show that over 109 ions can be accumulated with high efficiency in the present device and that the extent of subsequent compression is only limited by the space charge capacity of the trapping region. Approximately 5 × 109 charges introduced from an electrospray ionization source were trapped for a 40 s accumulation period, more than 2 orders of magnitude greater than the previously reported charge capacity of an ion funnel trap. Importantly, we show that extended ion accumulation in conjunction with CRIMP compression and multiple passes through the serpentine path provides the basis for a highly desirable combination of ultrahigh sensitivity and SLIM SUPER high-resolution IM separations.

Enzymatic Mechanism for Arabinan Degradation and Transport in the Thermophilic Bacterium Caldanaerobius polysaccharolyticus.

The plant cell wall polysaccharide arabinan provides an important supply of arabinose, and unraveling arabinan-degrading strategies by microbes is important for understanding its use as a source of energy. Here, we explored the arabinan-degrading enzymes in the thermophilic bacterium Caldanaerobius polysaccharolyticus and identified a gene cluster encoding two glycoside hydrolase (GH) family 51 α-l-arabinofuranosidases (CpAbf51A, CpAbf51B), a GH43 endoarabinanase (CpAbn43A), a GH27 ß-l-arabinopyranosidase (CpAbp27A), and two GH127 ß-l-arabinofuranosidases (CpAbf127A, CpAbf127B). The genes were expressed as recombinant proteins, and the functions of the purified proteins were determined with para-nitrophenyl (pNP)-linked sugars and naturally occurring pectin structural elements as the substrates. The results demonstrated that CpAbn43A is an endoarabinanase while CpAbf51A and CpAbf51B are α-l-arabinofuranosidases that exhibit diverse substrate specificities, cleaving α-1,2, α-1,3, and α-1,5 linkages of purified arabinan-oligosaccharides. Furthermore, both CpAbf127A and CpAbf127B cleaved ß-arabinofuranose residues in complex arabinan side chains, thus providing evidence of the function of this family of enzymes on such polysaccharides. The optimal temperatures of the enzymes ranged between 60°C and 75°C, and CpAbf43A and CpAbf51A worked synergistically to release arabinose from branched and debranched arabinan. Furthermore, the hydrolytic activity on branched arabinan oligosaccharides and degradation of pectic substrates by the endoarabinanase and l-arabinofuranosidases suggested a microbe equipped with diverse activities to degrade complex arabinan in the environment. Based on our functional analyses of the genes in the arabinan degradation cluster and the substrate-binding studies on a component of the cognate transporter system, we propose a model for arabinan degradation and transport by C. polysaccharolyticusIMPORTANCE Genomic DNA sequencing and bioinformatic analysis allowed the identification of a gene cluster encoding several proteins predicted to function in arabinan degradation and transport in C. polysaccharolyticus The analysis of the recombinant proteins yielded detailed insights into the putative arabinan metabolism of this thermophilic bacterium. The use of various branched arabinan oligosaccharides provided a detailed understanding of the substrate specificities of the enzymes and allowed assignment of two new GH127 polypeptides as ß-l-arabinofuranosidases able to degrade pectic substrates, thus expanding our knowledge of this rare group of glycoside hydrolases. In addition, the enzymes showed synergistic effects for the degradation of arabinans at elevated temperatures. The enzymes characterized from the gene cluster are, therefore, of utility for arabinose production in both the biofuel and food industries.