Bilateral Sternalis Muscles: The Clinical Significance of This Rare Discovery.

This case report explores the physical characteristics and clinical significance of the sternalis muscle, an uncommon anatomical variation of the anterior thoracic wall. If present, the sternalis muscle may distort diagnostic images and can be associated with incorrect interpretation of such medical images, misdiagnoses, and even surgical complications. As such, enhancing clinicians' knowledge of this muscle and improving its recognition is of the utmost importance. In this case report, a rare bilateral sternalis muscle that was discovered during an educational human cadaveric dissection of a 73-year-old Black male is described. The right sternalis muscle fibres extended from the mid-sternal level to the right sternocostal arch, measuring 11.5 cm in length and 3.4 cm at its largest width. In contrast, the smaller left sternalis muscle fibres measured only 5.6 cm in length and 1.2 cm at its greatest width. This rare bilateral presentation of the sternalis muscle is documented in approximately one-third of all reported sternalis cases with an associated estimated prevalence as low as 1.7% among the general population. Serving as a reminder of the intricate anatomical complexities that continue to challenge and intrigue medical professionals, this report advocates for continued education of anatomical variations to enhance patient care and medical practices.

Atypically Taut Superior Polar Splenic Artery Discovered in a Human Cadaver.

The splenic artery is the largest branch of the celiac trunk and frequently presents with anatomical variability. These variations relate to its origin, trajectory, location relative to the pancreas, terminal branching pattern, and the potential presence of polar arteries. Knowledge of the splenic artery's variability may inform gastrointestinal surgeons as they plan and execute surgical interventions, resulting in improved success rates while minimizing both operative complications and procedural time. The case presentation of a splenic artery dissected from an elderly male cadaver initially demonstrated normal anatomical arrangement. The artery branched off the celiac trunk of the abdominal aorta and followed a tortuous suprapancreatic route to split into two lobar arteries terminating in the spleen. However, upon closer inspection, a superior polar splenic artery was uncovered with two unique characteristics. Firstly, the presented polar artery lacked branching gastric arteries, a rare variation with a prevalence of only 3.27%. Secondly, the distance between the origin of the superior polar splenic artery and the splenic hilum was greater than what is often reported in clinical literature. While similar previous case reports have observed arterial origins of greater distance, these have often been accompanied by a compensatory arterial length. Interestingly, the case presented in this report contained a superior polar splenic artery with an arterial length shorter than its distance to the splenic hilum, resulting in an atypically taut vessel. This bears clinical importance, as this arterial presentation may be susceptible to a surgical rupture if neglected. By including this anatomical variation in the expanding library of splenic artery variations, surgeons and their collaborative healthcare teams may broaden their understanding of splenic artery anatomy as they conceptualize new techniques for pancreatomy and splenectomy procedures that consider arterial variations while minimizing surgical complications, operative time, and patient blood loss.

Healthcare-associated infections among neonates and children in Pakistan: findings and the implications from a point prevalence survey.

BACKGROUND: Healthcare-associated infections (HAIs) increase morbidity, mortality and costs. The overall prevalence of HAIs is greater in low- and middle-income countries due to poor resources and infrastructure, with the incidence of HAIs greater among neonates and children. There is a need to understand the current situation in Pakistan including key drivers to improve future care. METHODS: Point prevalence survey (PPS) of HAIs in the children's wards of 19 public sector secondary- and tertiary-care hospitals of Pakistan and associated key drivers. RESULTS: A total of 1147 children were included in the PPS. 35.7% were neonates with 32.8% aged >1-5 years. 35.2% were admitted to the intensive care units (ICUs). Peripheral, central venous and urinary catheters were present in 48%, 2.9% and 5.6% of the patients, respectively. A total of 161 HAIs from various pathogens were observed in 153 cases, giving a prevalence of 13.3%. The majority of HAIs were caused by Staphylococcus aureus (31.7%) followed by Klebsiella pneumoniae (22.9%) and Escherichia coli (17.4%). Bloodstream infections were identified in 42 cases followed by lower-respiratory-tract infections in 35. Increased length of hospital stays and being admitted to the ICU, 'rapidly fatal' patients under the McCabe and Jackson criteria, central and peripheral catheterization, and invasive mechanical ventilation were, associated with higher HAIs (P<0.001). 99.7% of HAI patients fully recovered and were discharged from the hospital. CONCLUSION: There is a high prevalence of HAIs among neonates and children admitted to health facilities in Pakistan. Infection prevention and control measures should be implemented to help prevent future HAIs.

Ultrafast fiber laser at 1570 nm based on organic material as saturable absorber.

In this work, we demonstrated Poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT: PSS) as a saturable absorber (SA) to produce mode-locking operation in different length of Erbium-doped fiber laser (EDFL). The PEDOT: PSS was embedded into polyvinyl alcohol to form a thin film that acts as an absorber into the laser setup. The three different mode-locked EDFL were successfully demonstrated with different cavity length and output coupler ratio. The pulse repetition rate/width of 3.417 MHz/710 fs, 4.831 MHz/510 fs, and 6.049 MHz/460 fs were obtained by utilizing optical coupler/ cavity length of 20:80/60.7 m, 10:90/42.7 m, and 5:95/33.7 m, respectively. All experiments generated a stable and mode-locked operation at a central wavelength of 1570.76 nm, 1570.3 nm, and 1569.95 nm with 3 dB bandwidth of 4.8 nm, 5.6 nm, and 6.5 nm, respectively. The long-time stability of the ultrafast fiber lasers was investigated for each setup via 120 min. The proposed PEDOT: PSS has proven as a promising material to induce mode-locking operation in different fiber laser setup.

Titanium dioxide fiber saturable absorber for Q-switched fiber laser generation in the 1-micrometer region: publisher's note.

This publisher's note serves to correct an error in Appl. Opt. 58, 3495 (2019)APOPAI0003-693510.1364/AO.58.003495.

Ultrafast soliton mode-locked fiber laser at 1560 nm based on Znq2 as a saturable absorber.

A mode-locked fiber laser was developed by using bis(8-hydroxyquinoline) zinc (Znq2) as a saturable absorber (SA). Znq2 is an organic metal chelate with several advantages such as good saturable absorption, relatively high damage threshold, and an easy, low-cost, and simple fabrication process. The developed SA based on Znq2 has a linear absorption (at 1560 nm), modulation depth, and saturation intensity of 1.2 dB, 16.6 %, and 95MW/cm2, respectively. The laser cavity produced a very stable soliton mode-locking operation at 1560.6 nm with pulse duration, repetition rate, and SNR of 1.46 ps, 3.5 MHz, and 60.6 dB, respectively. This work is the first, to the best of our knowledge, to report Znq2 as a mode locker.

ADAP is a possible negative regulator of glucosinolate biosynthesis in Arabidopsis thaliana based on clustering and gene expression analyses.

Glucosinolates (GSLs) are plant secondary metabolites consisting of sulfur and nitrogen, commonly found in Brassicaceae crops, such as Arabidopsis thaliana. These compounds are known for their roles in plant defense mechanisms against pests and pathogens. 'Guilt-by-association' (GBA) approach predicts genes encoding proteins with similar function tend to share gene expression pattern generated from high throughput sequencing data. Recent studies have successfully identified GSL genes using GBA approach, followed by targeted verification of gene expression and metabolite data. Therefore, a GSL co-expression network was constructed using known GSL genes obtained from our in-house database, SuCComBase. DPClusO was used to identify subnetworks of the GSL co-expression network followed by Fisher's exact test leading to the discovery of a potential gene that encodes the ARIA-interacting double AP2-domain protein (ADAP) transcription factor (TF). Further functional analysis was performed using an effective gene silencing system known as CRES-T. By applying CRES-T, ADAP TF gene was fused to a plant-specific EAR-motif repressor domain (SRDX), which suppresses the expression of ADAP target genes. In this study, ADAP was proposed as a negative regulator in aliphatic GSL biosynthesis due to the over-expression of downstream aliphatic GSL genes (UGT74C1 and IPMI1) in ADAP-SRDX line. The significant over-expression of ADAP gene in the ADAP-SRDX line also suggests the behavior of the TF that negatively affects the expression of UGT74C1 and IPMI1 via a feedback mechanism in A. thaliana.

Soliton mode-locked pulse generation with a bulk structured MXene Ti3AlC2 deposited onto a D-shaped fiber.

We propose a bulk structured MXene, Ti3AlC2 deposited onto D-shaped fiber for soliton generation in an erbium-doped fiber laser (EDFL) cavity. Our saturable absorber (SA) device, based on MAX phase, was prepared by using stirring and ultrasonic vibration, which offer easier sample preparation compared with its 2D counterparts. By means of the polishing wheel technique, we fabricated a D-shaped fiber with a controlled polishing depth and incorporated the MAX phase Ti3AlC2 solution onto its polishing region. We obtained a mode-locked soliton pulse with the proposed MAX phase D-shaped (MAX-DS) SA in EDFL cavity. The pulse width, repetition rate, and central wavelength of the pulse train are 2.21 ps, 1.89 MHz, and 1557.63 nm, respectively. The polarization-insensitive EDFL cavity initiated a soliton operation with superior stability as the pump power tuned from 21 to 131 mW; further, the ML laser exhibits an average power of 15.3 mW, peak power of 3.8 kW, and pump efficiency of 12.5%. The MAX-DS SA incorporated inside the EDFL reveals efficient output performance, with a pulse energy of 8.14 nJ, the highest ever reported, to our best knowledge, among D-shaped fiber-based SA.

Q-switched ytterbium-doped fiber laser based on evanescent field interaction with lutetium oxide.

We demonstrated lutetium oxide (${\textrm{Lu}_2}{\textrm{O}_3}$Lu2O3) deposited onto D-shaped fiber producing Q-switched ytterbium-doped fiber laser (YDFL) with an operating wavelength of 1037 nm. D-shaped fiber ${\textrm{Lu}_2}{\textrm{O}_3}$Lu2O3 as a saturable absorber (SA) was prepared using a polishing-wheel technique by polishing 2 times to establish an excellent evanescent field interaction between material and light on the surface of the polished region. The SA was deployed into a YDFL to generate Q-switching. The proposed D-shaped fiber ${\textrm{Lu}_2}{\textrm{O}_3}$Lu2O3 initiated pulses as short as 3.6 µs, with the highest repetition rate of 65.8 kHz. Stability of the SA is proven, as it produced stable pulses within the pump power of 99 to 133 mW with an SNR of 62.13 dB. Q-switched YDFL generates pulses with an output power of 0.93 to 1.99 mW and pulse energy of 17 to 30 nJ. We obtained a laser cavity with the optical-to-optical efficiency of 3.33%, which was the highest among D-shaped fiber-deposited SA materials in YDFL. Therefore, ${\textrm{Lu}_2}{\textrm{O}_3}$Lu2O3 deposited onto D-shaped fiber can be deployed as an SA in YDFL for a portable Q-switched laser source.

Passively Q-switched erbium-doped fiber laser utilizing tungsten oxide as a saturable absorber.

We demonstrated a passively $Q$Q-switched fiber laser utilizing tungsten oxide (${\rm WO_{3}}$WO3) thin film as a saturable absorber (SA). The ${\rm WO_{3} {\text -} SA}$WO3-SA was sandwiched as a polymer composite film between fiber ferrules in an erbium-doped fiber cavity. ${\rm WO_{3}}$WO3 exhibits high nonlinear optical response characterized by an appropriate modulation depth of 10% and a saturation intensity of ${100}\;{{\rm MW/cm}^2}$100MW/cm2. The fiber cavity starts to generate a stable pulse train whereby as the pump power increases from 45 to 165 mw, the repetition rate increases from 16.75 to 56.3 kHz, while the pulse width decreases from 13.8 to 4.3 µs. The $Q$Q-switched laser generated maximum pulse energy of 6.6 nJ obtained at 165 mW, which was the maximum pump power available by the used laser diode. This is, to the best of our knowledge, the first demonstration of a $Q$Q-switched fiber laser based on the ${\rm WO_{3} {\text -} SA}$WO3-SA, which could contribute as a new potential SA material in the field of pulsed fiber lasers.

Titanium dioxide fiber saturable absorber for Q-switched fiber laser generation in the 1-micrometer region.

A passively Q-switched ytterbium-doped fiber laser (YDFL) operating at 1062 nm was demonstrated by using a segment of 20 cm titanium dioxide-doped fiber saturable absorber (TiO2DF SA). The Q-switched YDFL emerged stably with tunable repetition rates ranging from 32 kHz to 53 kHz as the pump power rose from 109 mW to 233 mW. Within this range of pump power, a maximum output power of 10.1 mW, maximum peak power of 75 mW, and maximum pulse energy of 191 nJ were obtained. The narrowest pulse width of 2.55 µs was attained at the maximum pump power of 233 mW, while the signal-to-noise ratio of the fundamental frequency was 47 dB. This demonstration reveals that the proposed TiO2DF SA is feasible for constructing a flexible and reliably stable Q-switched pulsed fiber laser in the 1-micrometer region.

Mode-locking pulse generation with MoS2-PVA saturable absorber in both anomalous and ultra-long normal dispersion regimes.

We experimentally demonstrate a stable and simple mode locked erbium doped fiber laser (EDFL) utilizing passive few-layer molybdenum disulfide (MoS2) as a saturable absorber. The MoS2 is obtained by liquid phase exfoliation before it is embedded in a polymer composite film and then inserted in the laser cavity. A stable soliton pulse train started at a low threshold pump power of 20 mW in the anomalous dispersion regime after fine-tuning the rotation of the polarization controller. The central wavelength, 3 dB bandwidth, pulse width, and repetition rate of the soliton pulses are 1574.6 nm, 9.5 nm, 790 fs, and 29.5 MHz, respectively. By inserting a 850 m long dispersion shifted fiber (DSF) in the cavity, a dissipative soliton with square pulse train is obtained in the normal dispersion regime where the operating wavelength is centered at 1567.44 nm with a 3 dB bandwidth of 19.68 nm. The dissipative soliton pulse has a pulse width of 90 ns at a low repetition rate of 231.5 kHz due to the long DSF used. These results are a contribution to the pool of knowledge in nonlinear optical properties of two-dimensional nanomaterials especially for ultrafast photonic applications.

Tunable Q-switched fiber laser using zinc oxide nanoparticles as a saturable absorber.

Nanomaterials have ignited new interest due to their distinctive electronic, mechanical, and optical properties. Zinc oxide nanostructures are fabricated into thin film and then inserted between two fiber ferrules to act as a saturable absorber (SA). The modulation depth and insertion loss of the SA are 5% and 3.5 dB, respectively. When the ZnO-SA is incorporated into the laser cavity, a stable Q-switched pulse tunable from 1536 to 1586 nm (50 nm range) with pulse energy up to 46 nJ was observed. Our result suggests that ZnO is a promising broadband SA to generate passively Q-switched fiber lasers.

Tunable dual-wavelength ytterbium-doped fiber laser using a strain technique on microfiber Mach-Zehnder interferometer.

In this paper, stable dual-wavelength generation using a strain technique for a ytterbium-doped fiber laser is successfully demonstrated. A microfiber-based Mach-Zehnder interferometer is inserted into the laser ring cavity and stretched using the xyz translation stage. Four sets of dual-wavelength output lasing are obtained when the strain is applied onto a microfiber. The dual-wavelength output possesses spacing between 7.12 and 11.59 nm, with displacement from 2 to 190 µm from the central wavelength. The obtained side-mode suppression ratio is ∼48 dBm, while the maximum power fluctuation and wavelength shift are less than 0.6 dB and 0.01 nm, respectively. The results demonstrate that this setup generates a stable dual-wavelength laser in the 1 µm region.

Passively Q-switched erbium-doped fiber laser at C-band region based on WS2 saturable absorber.

We demonstrate a Q-switched erbium-doped fiber laser using tungsten disulfide (WS2) as a saturable absorber. The WS2 is deposited onto fiber ferrules using a drop-casting method. Passive Q-switched pulses operating in the C-band region with a central wavelength of 1560.7 nm are successfully generated by a tunable pulse repetition rate ranging from 27.2 to 84.8 kHz when pump power is increased from 40 to 220 mW. At the same time, the pulse width decreases from a maximum value of 3.84 µs to a minimum value of 1.44 µs. The signal-to-noise ratio gives a stable value of 43.7 dB. The modulation depth and saturation intensity are measured to be 0.99% and 36.2 MW/cm², respectively.

A Stable Dual-wavelength Thulium-doped Fiber Laser at 1.9 µm Using Photonic Crystal Fiber.

A stable dual-wavelength thulium-doped fiber laser operating at 1.9 µm using a short length of photonic crystal fiber (PCF) has been proposed and demonstrated. The photonics crystal fiber was 10 cm in length and effectively acted as a Mach-Zehnder interferometry element with a free spectral range of 0.2 nm. This dual-wavelength thulium-doped fiber laser operated steadily at room temperature with a 45 dB optical signal-to-noise-ratio.

Multiwall carbon nanotube polyvinyl alcohol-based saturable absorber in passively Q-switched fiber laser.

In this work, we demonstrated a compact Q-switched erbium-doped fiber laser capable of generating high-energy pulses using a newly developed multiwall carbon nanotube (CNT) polyvinyl alcohol (PVA) thin film based saturable absorber. Q-switched pulse operation is obtained by sandwiching the thin film between two fiber ferrules forming a saturable absorber. A saturable absorber with 1.25 wt. % of PVA concentration shows a consistency in generating pulsed laser with a good range of tunable repetition rate, shortest pulse width, and produces a high pulse energy and peak power. The pulse train generated has a maximum repetition rate of 29.9 kHz with a corresponding pulse width of 3.49 µs as a function of maximum pump power of 32.15 mW. The maximum average output power of the Q-switched fiber laser system is 1.49 mW, which translates to a pulse energy of 49.8 nJ. The proposed method of multiwall CNT/PVA thin film fabrication is low in cost and involves uncomplicated processes.

Tunable single Stokes extraction from 20 GHz Brillouin fiber laser using ultranarrow bandwidth optical filter.

The individual extraction of a Brillouin Stokes line from a 20 GHz comb generated from the compact configuration of a multiwavelength Brillouin fiber ring laser configuration has been achieved using an ultranarrow bandwidth (UNB) optical filter. The narrowest bandwidth transmission of a UNB optical filter that is 50 pm is used in order to get particular Stokes. The Stokes filtered is in the wavelength range of 1549.768-1551.016 nm. High SNR within the range of 54.97-11.73 dB with almost nil peak power loss being obtained was monitored by a 0.16 pm optical spectrum analyzer, giving convincing results. Relatively, the proposed configuration could provide wide tunability and narrow selection of the Brillouin Stokes.

Closely spaced dual-wavelength fiber laser using an ultranarrow bandwidth optical filter for low radio frequency generation.

A dual-wavelength (DW) fiber laser with a closely spaced single longitudinal mode (SLM) output is proposed and demonstrated. The proposed fiber laser utilizes a conventional fiber Bragg grating with a center wavelength of about 1546.8 nm in conjunction with an ultranarrow bandwidth tunable optical filter to generate the desired DW SLM output. Observations with a very high resolution optical spectrum analyzer, which was capable of achieving resolutions up to 0.16 pm, revealed detailed spectral characteristics not characteristically seen before. A channel spacing of up to 58 nm was realized, and spacing as small as 2 pm was achieved. The minimum channel spacing and its resulting beat frequency are the narrowest observed yet to the best of our knowledge for a DW fiber laser at room temperature.