Tuning the Solubility of Soluble Support Constructs in Liquid Phase Oligonucleotide Synthesis.

Solubility of the growing oligonucleotide-soluble support constructs in the liquid phase oligonucleotide synthesis (LPOS) is a critical parameter, which affects coupling efficiency, purity, and recovery of the growing oligonucleotides during the chain elongation. In the present study, oligonucleotides have been assembled on a 4-oxoheptanedioic acid (OHDA) linker-derived tetrapodal soluble support using 5'-O-(2-methoxyprop-2-yl)-protected 2'-deoxyribonucleotide phosphoroamidite building blocks with different nucleobase protecting groups [isobutyryl (Gua), 1-butylpyrrolidin-2-ylidene (Gua, Cyt), 2,4-dimethylbenzoyl (Ade, Cyt), and Bz (Thy)]. The solubility of the oligonucleotide-soluble support constructs (molecular mass varying between 3 and 10 kDa) as models of protected tetra-, octa-, dodeca-, hexadeca-, and eicosa-nucleotides was measured in different solvent systems and in potential antisolvents. By tuning the nucleobase protecting group scheme, the solubility can be improved in aprotic organic solvent systems, while the recovery of the constructs in the precipitation, used for the isolation and purification of the growing oligonucleotide intermediates in a protic antisolvent (2-propanol), remained near quantitative. The precipitation-based yield of the protected tetrapodal oligonucleotides varied from a quantitative to 90% yield. Overall yield (for di-: 95%, tri-: 79-96%, tetra-: 82-88%, and pentanucleotides: 68-75%) and purity of the LPOS were evaluated by RP HPLC and MS-spectroscopy of the released oligonucleotide aliquots. In addition, the orthogonality of the OHDA linker was applied to release authentic protected nucleotides from the soluble supports.

Increasing cadence with a metronome and running barefoot changes the sagittal kinematics of the lower limbs and trunk.

The purpose was to compare two non-laboratory based running retraining programs on lower limb and trunk kinematics in recreational runners. Seventy recreational runners (30 ± 7.3 years old, 40% female) were randomised to a barefoot running group (BAR), a group wearing a digital metronome with their basal cadence increased by 10% (CAD), and a control group (CON). BAR and CAD groups included intervals from 15 to 40 min over 10 weeks and 3 days/week. 3D sagittal kinematics of the ankle, knee, hip, pelvis, and trunk were measured before and after the retraining program, at comfortable and high speeds. A 3 × 2 mixed ANOVA revealed that BAR and CAD groups increased knee and hip flexion at footstrike, increased peak hip flexion during stance and flight phase, decreased peak hip extension during flight phase, and increased anterior pelvic tilt at both speeds after retraining. In addition, BAR increased ankle plantar flexion at footstrike and increased anterior trunk tilt. Both retraining programs demonstrated significant moderate to large effect size changes in parameters that could reduce the mechanical risks of injury associated with excessive knee stress, which is of interest to coaches, runners and those prescribing rehabilitation and injury prevention programs.

Effects of Plyometric Training on Running Biomechanics and Jumping Ability of U14 Athletes.

ABSTRACT: Cardiel-Sánchez, S, Rubio-Peirotén, A, Molina-Molina, A, García-Cebadera Gómez, C, Almenar-Arasanz, A, Ráfales-Perucha, A, Roche-Seruendo, LE, and Cartón-Llorente, A. Effects of plyometric training on running biomechanics and jumping ability of U14 athletes. J Strength Cond Res XX(X): 000-000, 2024-Children under the age of 14 years (U14) are particularly susceptible to musculoskeletal disorders because of growth spurts. Plyometric training has been shown to be beneficial for both injury reduction and performance enhancement. The aim of this study was to evaluate the effects of plyometric training on the jumping ability and running biomechanics of U14 track-and-field athletes. A single-blind randomized controlled trial was conducted. Thirty-five (18 female and 17 male) U14 athletes (age: 12.5 ± 1.2 years; height: 152.3 ± 7.7 cm; body mass: 47.3 ± 6.9 kg) were randomized into experimental and control groups. All subjects completed their usual training for 4 weeks, and those in the intervention group added a low-volume plyometric program twice a week. Preintervention and postintervention assessments included a countermovement jump (CMJ) to determine maximum jump height, 10-second repeated jumps to assess reactive strength index (RSI), and a 3-minute run at 12 km·h-1 to analyze running kinematics contact time, flight time, step length (SL), step frequency (SF), mean power output, vertical spring stiffness, and leg spring stiffness (LSS). The results revealed no main effect of time for any of the variables. A group-by-time interaction was found for RSI (p = 0.045) in the intervention group, whereas a significant increase in LSS was also found after the intervention (p = 0.031). However, no changes in CMJ height or other running parameters were observed. The significance level for the study was set at ρ ≤ 0.05. Plyometric-jump training may improve the stretch-shortening cycle in U14 athletes by increasing RSI and LSS. Athletes and coaches in running-related sports should be aware of these short-term effects when aiming to optimize the energy storage and release mechanism.

Stereo-Controlled Liquid Phase Synthesis of Phosphorothioate Oligonucleotides on a Soluble Support.

5'-O-(2-Methoxyisopropyl) (MIP)-protected 2'-deoxynucleosides as chiral P(V)-building blocks, based on the limonene-derived oxathiaphospholane sulfide, were synthesized and used for the assembly of di-, tri-, and tetranucleotide phosphorothioates on a tetrapodal pentaerythritol-derived soluble support. The synthesis cycle consisted of two reactions and two precipitations: (1) the coupling under basic conditions, followed by neutralization and precipitation and (2) an acid catalyzed 5'-O-deacetalization, followed by neutralization and precipitation. The simple P(V) chemistry together with the facile 5'-O-MIP deprotection proved efficient in the liquid phase oligonucleotide synthesis (LPOS). Ammonolysis released nearly homogeneous Rp or Sp phosphorothioate diastereomers in ca. 80% yield/synthesis cycle.

Real-time, in situ measurement of H2O generated during in situ combustion tests using 1f-normalized wavelength modulation spectroscopy with second harmonic detection.

The development and deployment of a real-time, in situ, non-invasive sensor to monitor the concentration of H 2 O during in situ combustion (ISC) experiments with a heavy-crude oil is described. A real-time sensor to monitor the gas-phase products from ISC can support the study of the kinetics of the complex chemical reactive system in ISC. The mole fraction of H 2 O was measured using tunable diode laser (TDL) absorption spectroscopy coupled with 1f-normalized wavelength modulation spectroscopy (WMS) and 2f detection. The WMS 2f/1f strategy was used to enhance sensitivity with effective noise rejection, particularly suitable when characterizing the water vapor evolved from oil-water emulsions. H 2 O was measured at 3934.10c m -1 from the fundamental band v 3. That transition was selected using the HITRAN database to increase the line strength and minimize interference from neighbor compounds. Measurements of H 2 O concentration were conducted at ambient temperature and pressure using a reference cell (H 2 O=2% at 98.6 kPa) to validate the sensor architecture under controlled laboratory environments. The TDL sensor was also successfully validated during real ISC experiments involving heavy-crude oil. Validation and combustion experiments showed the potential of the TDL-based sensor for non-invasive, real-time, in situ measurements of gas-phase species in conditions similar to those of laboratory-scale experimental ISC tests.

High-intensity Actions in Elite Soccer: Current Status and Future Perspectives.

Over the years, soccer has become more physically demanding; the number and frequency of high-intensity actions have increased, and these activities are decisive in determining the match outcome. Importantly, the reductionist approach commonly used to analyze high-intensity actions does not contemplate a more contextualized perspective on soccer performance. Traditionally, most investigations have only provided quantitative data regarding sprints (i. e. time, distances, frequency) without examining "how" (e. g. type of trajectory or starting position) and "why" (e. g. tactical role) soccer players sprint. In fact, other high-intensity actions, apart from running, are not even mentioned (i. e. curve sprints, change of direction, and specific-jump tasks). This has led to the use of tests and interventions that do not accurately reflect real game actions. Given the true technical-tactical-physical demands of each playing position, this narrative review collected a wide-spectrum of current soccer-related articles and provided a discussion regarding high-intensity actions, with a positional-based approach. In this narrative review, practitioners are encouraged to contemplate and consider the different elements that characterize high-intensity actions in soccer, in order to assess and train soccer players under a more sport-specific and integrative perspective.

Level of Agreement between the MotionMetrix System and an Optoelectronic Motion Capture System for Walking and Running Gait Measurements.

Markerless motion capture systems (MCS) have been developed as an alternative solution to overcome the limitations of 3D MCS as they provide a more practical and efficient setup process given, among other factors, the lack of sensors attached to the body. However, this might affect the accuracy of the measures recorded. Thus, this study is aimed at evaluating the level of agreement between a markerless MSC (i.e., MotionMetrix) and an optoelectronic MCS (i.e., Qualisys). For such purpose, 24 healthy young adults were assessed for walking (at 5 km/h) and running (at 10 and 15 km/h) in a single session. The parameters obtained from MotionMetrix and Qualisys were tested in terms of level of agreement. When walking at 5 km/h, the MotionMetrix system significantly underestimated the stance and swing phases, as well as the load and pre-swing phases (p < 0.05) reporting also relatively low systematic bias (i.e., ≤ -0.03 s) and standard error of the estimate (SEE) (i.e., ≤0.02 s). The level of agreement between measurements was perfect (r > 0.9) for step length left and cadence and very large (r > 0.7) for step time left, gait cycle, and stride length. Regarding running at 10 km/h, bias and SEE analysis revealed significant differences for most of the variables except for stride time, rate and length, swing knee flexion for both legs, and thigh flexion left. The level of agreement between measurements was very large (r > 0.7) for stride time and rate, stride length, and vertical displacement. At 15 km/h, bias and SEE revealed significant differences for vertical displacement, landing knee flexion for both legs, stance knee flexion left, thigh flexion, and extension for both legs. The level of agreement between measurements in running at 15 km/h was almost perfect (r > 0.9) when comparing Qualisys and MotionMetrix parameters for stride time and rate, and stride length. The agreement between the two motion capture systems varied for different variables and speeds of locomotion, with some variables demonstrating high agreement while others showed poor agreement. Nonetheless, the findings presented here suggest that the MotionMetrix system is a promising option for sports practitioners and clinicians interested in measuring gait variables, particularly in the contexts examined in the study.

RunScribe Sacral Gait Lab™ Validation for Measuring Pelvic Kinematics during Human Locomotion at Different Speeds.

Optoelectronic motion capture systems are considered the gold standard for measuring walking and running kinematics parameters. However, these systems prerequisites are not feasible for practitioners as they entail a laboratory environment and time to process and calculate the data. Therefore, this study aims to evaluate the validity of the three-sensor RunScribe Sacral Gait Lab™ inertial measurement unit (IMU) in measuring pelvic kinematics in terms of vertical oscillation, tilt, obliquity, rotational range of motion, and the maximum angular rates during walking and running on a treadmill. Pelvic kinematic parameters were measured simultaneously using an eight-camera motion analysis system (Qualisys Medical AB, GÖTEBORG, Sweden) and the three-sensor RunScribe Sacral Gait Lab™ (Scribe Lab. Inc. San Francisco, CA, USA) in a sample of 16 healthy young adults. An acceptable level of agreement was considered if the following criteria were met: low bias and SEE (<0.2 times the between-subject differences SD), almost perfect (r > 0.90), and good reliability (ICC > 0.81). The results obtained reveal that the three-sensor RunScribe Sacral Gait Lab™ IMU did not reach the validity criteria established for any of the variables and velocities tested. The results obtained therefore show significant differences between the systems for the pelvic kinematic parameters measured during both walking and running.

Synthesis of Phosphorodiamidate Oligonucleotide Dimers.

Azido nucleosides couple with phosphoramidites via an initial iminophosphorane, which eliminates acrylonitrile to generate the coupled dimer P(V) product. The vulnerable phosphite triester intermediate is bypassed entirely, making the methodology very suitable to solution-phase synthesis. This new coupling protocol requires no protection of the 5'-OH function and provides a new method of installing internucleosidic phosphorodiamidate bonds with near quantitative yields.

Design and NMR characterization of reversible head-to-tail boronate-linked macrocyclic nucleic acids.

Inspired by the ability of boronic acids to bind with compounds containing diol moieties, we envisioned the formation in solution of boronate ester-based macrocycles by the head-to-tail assembly of a nucleosidic precursor that contains both a boronic acid and the natural 2',3'-diol of ribose. DOSY NMR spectroscopy experiments in water and anhydrous DMF revealed the dynamic assembly of this precursor into dimeric and trimeric macrocycles in a concentration-dependent fashion as well as the reversibility of the self-assembly process. NMR experimental values and quantum mechanics calculations provided further insight into the sugar pucker conformation profile of these macrocycles.

Effects of integrative neuromuscular training on the gait biomechanics of children with overweight and obesity.

OBJECTIVE: To analyze whether 13 weeks of integrative neuromuscular training can benefit spatiotemporal and kinematic parameters of gait in children with overweight/obesity. METHODS: This is a non-randomized controlled trial. Fifty children (10.77 ± 1.24 years, 31 girls) with overweight/obesity were allocated to an exercise group (EG) (n = 25) that carried out a 13-week exercise program based on fundamental movement skills, strength activities and aerobic training, and a control group (CG) (n = 25) that followed their normal lifestyle. Spatiotemporal (i.e., cadence, stance and support times, step length, and stride width) and kinematic (i.e., hip, pelvis, knee, and ankle angles) parameters were evaluated under laboratory conditions through a 3D analysis. ANCOVA was used to test raw and z-score differences between the EG and CG at post-exercise, adjusting for pre-exercise values. RESULTS: The EG maintained their baseline stance and single-limb support times while the CG increased them during walking (groups' difference: 3.1 and 1.9 centiseconds). The EG maintained baseline maximum foot abduction angle during the stance phase whereas the CG showed an increase (groups' difference: 3.9º). Additional analyses on kinematic profiles demonstrated that the EG walked with similar pelvic tilt and ankle abduction angles at post-exercise, while the CG increased the pelvic anterior tilt in the whole stance phase (mean groups' difference: 7.7º) and the ankle abduction angles in early- and mid-stance phases (mean groups' difference: 4.6º). No changes were observed in the rest of spatiotemporal and kinematic parameters. CONCLUSIONS: The integrative neuromuscular training stopped the progression of some biomechanical alterations during walking in children with overweight/obesity. These findings could contribute to preventing common movement-derived musculoskeletal disorders in this population, as well as preserving an optimal mechanical efficiency during walking.

The effect of two retraining programs, barefoot running vs increasing cadence, on kinematic parameters: A randomized controlled trial.

The aim of this study was to compare the effects of two 10-week non-laboratory-based running retraining programs on foot kinematics and spatiotemporal parameters in recreational runners. One hundred and three recreational runners (30 ± 7.2 years old, 39% females) were randomly assigned to either: a barefoot retraining group (BAR) with 3 sessions/week over 10 weeks, a cadence retraining group (CAD) who increased cadence by 10% again with 3 sessions/week over 10 weeks and a control group (CON) who did not perform any retraining. The footstrike pattern, footstrike angle (FSA), and spatial-temporal variables at comfortable and high speeds were measured using 2D/3D photogrammetry and a floor-based photocell system. A 3 × 2 ANOVA was used to compare between the groups and 2 time points. The FSA significantly reduced at the comfortable speed by 5.81° for BAR (p < 0.001; Cohen's d = 0.749) and 4.81° for CAD (p = 0.002; Cohen's d = 0.638), and at high speed by 6.54° for BAR (p < 0.001; Cohen's d = 0.753) and by 4.71° for CAD (p = 0.001; Cohen's d = 0.623). The cadence significantly increased by 2% in the CAD group (p = 0.015; Cohen's d = 0.344) at comfortable speed and the BAR group showed a 1.7% increase at high speed. BAR and CAD retraining programs showed a moderate effect for reducing FSA and rearfoot prevalence, and a small effect for increasing cadence. Both offer low-cost and feasible tools for gait modification within recreational runners in clinical scenarios.

Influence of the Shod Condition on Running Power Output: An Analysis in Recreationally Active Endurance Runners.

Several studies have already analysed power output in running or the relation between VO2max and power production as factors related to running economy; however, there are no studies assessing the difference in power output between shod and barefoot running. This study aims to identify the effect of footwear on the power output endurance runner. Forty-one endurance runners (16 female) were evaluated at shod and barefoot running over a one-session running protocol at their preferred comfortable velocity (11.71 ± 1.07 km·h−1). The mean power output (MPO) and normalized MPO (MPOnorm), form power, vertical oscillation, leg stiffness, running effectiveness and spatiotemporal parameters were obtained using the Stryd™ foot pod system. Additionally, footstrike patterns were measured using high-speed video at 240 Hz. No differences were noted in MPO (p = 0.582) and MPOnorm (p = 0.568), whereas significant differences were found in form power, in both absolute (p = 0.001) and relative values (p < 0.001), running effectiveness (p = 0.006), stiffness (p = 0.002) and vertical oscillation (p < 0.001). By running barefoot, lower values for contact time (p < 0.001) and step length (p = 0.003) were obtained with greater step frequency (p < 0.001), compared to shod running. The prevalence of footstrike pattern significantly differs between conditions, with 19.5% of runners showing a rearfoot strike, whereas no runners showed a rearfoot strike during barefoot running. Running barefoot showed greater running effectiveness in comparison with shod running, and was consistent with lower values in form power and lower vertical oscillation. From a practical perspective, the long-term effect of barefoot running drills might lead to increased running efficiency and leg stiffness in endurance runners, affecting running economy.

Oligonucleotides containing 2'-O-methyl-5-(1-phenyl-1,2,3-triazol-4-yl)uridines demonstrate increased affinity for RNA and induce exon-skipping in vitro.

The nucleotide monomer containing the 1-phenyl-1,2,3-triazole group attached to the 5-position of 2'-O-methyluridine is hereby presented together with a derivative further substituted with a p-sulfonamide group on the phenyl ring. Both were conveniently synthesised, and synergistic effect of the modifications were demonstrated when introduced into oligonucleotides and hybridised to complementary RNA. The combination of stacking of the phenyltriazoles and the conformational steering from the 2'-OMe group gave thermally very stable duplexes. Exon skipping in the distrophin transcript using 20-mer 2'-OMePS sequences with two phenyltriazoles introduced in different positions with and without the sulfonamide demonstrated efficient exon skipping but at the same level as the 2'-OMePS reference ASO.

Path Planning Generator with Metadata through a Domain Change by GAN between Physical and Virtual Environments.

Increasingly, robotic systems require a level of perception of the scenario to interact in real-time, but they also require specialized equipment such as sensors to reach high performance standards adequately. Therefore, it is essential to explore alternatives to reduce the costs for these systems. For example, a common problem attempted by intelligent robotic systems is path planning. This problem contains different subsystems such as perception, location, control, and planning, and demands a quick response time. Consequently, the design of the solutions is limited and requires specialized elements, increasing the cost and time development. Secondly, virtual reality is employed to train and evaluate algorithms, generating virtual data. For this reason, the virtual dataset can be connected with the authentic world through Generative Adversarial Networks (GANs), reducing time development and employing limited samples of the physical world. To describe the performance, metadata information details the properties of the agents in an environment. The metadata approach is tested with an augmented reality system and a micro aerial vehicle (MAV), where both systems are executed in an authentic environment and implemented in embedded devices. This development helps to guide alternatives to reduce resources and costs, but external factors limit these implementations, such as the illumination variation, because the system depends on only a conventional camera.

Fatness and fitness in relation to functional movement quality in overweight and obese children.

This study aimed to investigate the independent and combined associations between several fatness indicators and fitness components with functional movement quality in overweight/obese children. A total of 56 children (33 girls, aged 8-12) classified as overweight/obese according to the World Obesity Federation standard cut points, participated in this study. Participants underwent assessments of fatness [body mass index (BMI), waist circumference, and bioelectrical impedance measures], fitness [1 repetition maximum bench and leg press, and ALPHA test battery], and functional movement quality [4 tests from Functional Movement Screen TM (FMS)]. All fatness outcomes, except waist circumference, were negatively associated with total FMS score, after controlling for cardiorespiratory fitness. Cardiorespiratory fitness, lower limbs muscle strength, and speed-agility were positively associated with the total FMS score, regardless of BMI. Our results suggest that children with greater fatness indicators demonstrate lower functional movement quality independently of their fitness level, whereas children with better fitness level (i.e. cardiorespiratory fitness, lower limbs muscular strength, and speed-agility) demonstrate greater functional movement quality independently of their fatness level. However, children´s weight status seems to be more determinant than their fitness level in terms of functional movement quality, whereas being fit seems to moderately attenuate the negative influence of fatness.

RNA-based boronate internucleosidic linkages: an entry into reversible templated ligation and loop formation.

The use of templates able to control the assembly and disassembly of supramolecular biopolymers is an attractive approach with applications ranging from engineering new biopolymers to the modulation of complex biological systems. Self-assembled nucleic acid-based systems hold thus substantive potential for the construction of well-defined and stimuli-responsive molecular architectures. We report here for the first time the synthesis of a 5'-boronoribonucleotidic phosphoramidite building block, its incorporation at the 5' extremities of RNA sequences, and its ability to generate boronate internucleosidic linkages by RNA- and DNA-templated ligation. Moreover, melting denaturation studies also revealed that 5'-boronic acid ended RNA sequences are able to promote the formation of RNA loops in the presence of RNA templating partners. Molecular-dynamics (MD) simulations were used to model the structural parameters governing these processes.

Development of a tunable diode laser sensor for CO concentration analysis at laboratory-scale conditions for in situ combustion tests of heavy crude oils.

A tunable diode laser-based sensor is reported to monitor carbon monoxide (CO) concentration under conditions similar to those of laboratory-scale tests used to characterize the behavior of heavy crude oil during in situ combustion (ISC). The sensor uses a DFB diode laser operating over the spectral range of the rotational transition R(11) of the first overtone, wherein simulations of spectral absorption bands for CO, CO2, and H2O showed minimal spectral interference. The absorption spectra were calculated using the HiTran 2008 database at temperatures varying between 150°C and 800°C, pressures from 1 to 5 atm, and the typical concentration of major species in ISC characterization experiments. The measurements of CO concentration were conducted at ambient temperature and pressure in a static glass cell of borosilicate, with a path length of 3.81 cm, to validate the CO sensor architecture under controlled laboratory environments. The calibration curve for CO obtained by quantifying the optical density at the line center of R(11) for a molar-concentration range between 0.7% and 3.4% demonstrated a linear response (coefficient of determination of 0.9986). Experiments at 4 atm and 600 K were carried out in a custom-designed optical chamber with two optical wedged sapphire windows (2°) to avoid the etalon effect. CO-absorption spectra were validated by a comparative study with the HiTran database, while a calibration-free methodology using scanned-wavelength direct absorption was investigated for future characterizing experiments involving ISC. Signal to noise ratios (SNRs) were above 40 in the optical chamber and higher than 14 in the glass cell. The TDL sensor was also successfully validated during real ISC experiments involving Colombian heavy crude oil. The calibration and oxidation experiments showed the potential of TDL-based sensors in the region of 2.3 µm for non-invasive, real-time, and in situ measurements of carbon monoxide generated at similar conditions to those of lab-scale experimental ISC tests.

Preparation of a disulfide-linked precipitative soluble support for solution-phase synthesis of trimeric oligodeoxyribonucleotide 3´-(2-chlorophenylphosphate) building blocks.

The preparation of a disulfide-tethered precipitative soluble support and its use for solution-phase synthesis of trimeric oligodeoxyribonucleotide 3´-(2-chlorophenylphosphate) building blocks is described. To obtain the building blocks, N-acyl protected 2´-deoxy-5´-O-(4,4´-dimethoxytrityl)ribonucleosides were phosphorylated with bis(benzotriazol-1-yl) 2-chlorophenyl phosphate. The "outdated" phosphotriester strategy, based on coupling of P(V) building blocks in conjunction with quantitative precipitation of the oligodeoxyribonucleotide with MeOH is applied. Subsequent release of the resulting phosphate and base-protected oligodeoxyribonucleotide trimer 3'-pTpdC(Bz)pdG(ibu)-5' as its 3'-(2-chlorophenyl phosphate) was achieved by reductive cleavage of the disulfide bond.

Solution phase synthesis of short oligoribonucleotides on a precipitative tetrapodal support.

An effective method for the synthesis of short oligoribonucleotides in solution has been elaborated. Novel 2'-O-(2-cyanoethyl)-5'-O-(1-methoxy-1-methylethyl) protected ribonucleoside 3'-phosphoramidites have been prepared and their usefulness as building blocks in RNA synthesis on a soluble support has been demonstrated. As a proof of concept, a pentameric oligoribonucleotide, 3'-UUGCA-5', has been prepared on a precipitative tetrapodal tetrakis(4-azidomethylphenyl)pentaerythritol support. The 3'-terminal nucleoside was coupled to the support as a 3'-O-(4-pentynoyl) derivative by Cu(I) promoted 1,3-dipolar cycloaddition. Couplings were carried out with 1.5 equiv of the building block. In each coupling cycle, the small molecular reagents and byproducts were removed by two quantitative precipitations from MeOH, one after oxidation and the second after the 5'-deprotection. After completion of the chain assembly, treatment with triethylamine, ammonia and TBAF released the pentamer in high yields.