Advanced packaging continues to attract a lot of attention as the demands for higher performance, higher bandwidth, and lower power consumption increase. To satisfy aforementioned demands, researchers have tuned to 3D IC technology such as X-Cube using micro-bumps announced by Samsung in 2020. As much higher I/O bandwidth with smaller form factor is required, hybrid Cu bonding (HCB) is considered as one of the most promising technologies for the next-generation 3D-based chip products. Unlike the conventional solder based chip bonding, HCB can achieve fine pitch bonding by connecting copper-to-copper and oxide-to-oxide directly. HCB technology enables sub 10 um bonding pitch as well as improves electrical performance with no power and signal penalty. However, there are many challenges affecting HCB interface quality. Detailed understanding and analyses are necessary to obtain reliable fine pitch interconnects. In this paper, key factors, which impact the electrical connectivity and reliability of HCB, are investigated using die-to-wafer HCB chip with 4-μm pitch and 2-μm pad. The dishing and bonding accuracy are analyzed and precisely controlled to achieve robust electrical connection. As an effort to achieve void free interconnects, the characteristics of voids according to the type and size of particles are analyzed quantitatively. The electrical connectivity and reliability were demonstrated through the investigations of key factors of HCB. It was verified over 98% electrical connectivity for all 210 chains on the chip. All the chips both large top and small top structures, that were assigned to each category of reliability tests, including TC, u-HAST, and HTS, passed the package level reliability tests.

The somatostatin analog octreotide has recently been introduced in the treatment of infants with chylothorax. The safety profile of octreotide has not been fully evaluated. Octreotide reduces the splanchnic blood flow in a dose-dependent manner, affecting the entire gastrointestinal tract. Some concern has been recently raised regarding the potential implications of this effect in the development of necrotizing enterocolitis in neonates receiving octreotide for congenital hyperinsulinism or chylothorax. To our knowledge, there is no case report linking the use of octreotide with necrotizing enterocolitis in Korea. We report a case of serious necrotizing enterocolitis in a neonate treated with octreotide for congenital idiopathic chylothorax.

Objective: To investigate the effect of incomplete antenatal corticosteroid therapy (ACST) prior to delivery on clinical outcomes of preterm infants. Methods: Preterm infants born between 24 0/7 and 33 6/7 weeks of gestation from 2010 through 2016 were included and divided into the three groups according to the ACST; the no ACST group, the incomplete ACST group (inadequate dose of antenatal corticosteroid in pregnancy), and the complete ACST group (recommended dose of antenatal corticosteroid in pregnancy). The effect of risk factors including ACST on clinical outcomes of preterm infants was further explored using logistic regression analysis. Results: Among 198 infants who fulfilled the study criteria, 32 (16.2%) were classified as the no ACST group, 71 (35.9%) as the incomplete ACST group, and 95 (48.0%) as the complete ACST group. The incidence of low Apgar score at 5-minutes (≤4) was significantly higher in the no ACST group than in the complete ACST group (adjusted odds ratio [OR] 4.49; 95% confidence interval [CI] 1.41-14.32; P=0.011). The incidence of necrotizing enterocolitis (NEC, stage ≥2a) was not different between the no ACST group and the incomplete/the complete group, but significantly higher in the incomplete ACST group than in the complete ACST group (adjusted OR 10.49; 95% CI 1.13-97.28; P=0.039). Conclusion: Incomplete ACST within 24 hours prior to delivery appears to significantly increase NEC (stage ≥2a) in preterm infants born between 24 0/7 and 33 6/7 weeks gestation.

We present a fiber-optic dual-confocal laser caliper method for noncontact high-precision sensing and measuring thickness and refractive index of intraocular lens (IOL) implants. The principle of the method is based on sensing and measuring the confocal intensity response of the laser beam reflection from the opposite object surfaces, which provides the advanced feature of having no limitations on the object shape, thickness, and transparency. Using single-mode optical fibers and a 658-nm laser source, the thickness measurement accuracy was assessed to be as high as 5 pm. In addition, refractive index of a transparent object with thickness smaller than the working distance of the focusing lenses can be measured. The thickness and refractive index of a planoconvex IOL were measured with a high accuracy. (C) The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License.

Neonates, especially extremely low birth weight infants, are among the groups of patients undergoing transfusion frequently. Since they are exposed to higher specific transfusion risks compared to the patients of other age groups, there are many special aspects that must be considered for transfusion therapy in neonates. The transfusion risks in neonates include adverse outcomes specific for preterm infants as well as increased metabolic, immunologic, and infectious complications. To reduce the risks of transfusion-transmitted cytomegalovirus infection and transfusion-associated graft-versus-host disease, leukoreduced and irradiated cellular blood products should be used for all neonates. This review summarizes the risks of neonatal transfusion therapy, specific methods to reduce risk, and current trends and practices of red blood cell and platelet transfusions in neonates, to facilitate decision-making for neonatal transfusion.

Neonatal brain abscess is a very rare disease. Despite improvement of survival rate of premature infants due to the development of neonatal intensive therapy, it is still one of the important causes of death or sequelae of neonate. Fungal infection is unusual cause of neonatal brain abscess and the neonatal fungal brain abscess is a secondary result of hematogenous seeding that is rarely discovered primarily. We present a case of incidentally discovered multiple disseminated fungal brain abscess in asymptomatic very low birth weight infant.

We performed the feasibility study using speckle variance optical coherence tomography (SvOCT) to monitor the thermally induced protein denaturation and coagulation process as a function of temperature and depth. SvOCT provided the depth-resolved image of protein denaturation and coagulation with microscale resolution. This study was conducted using egg white. During the heating process, as the temperature increased, increases in the speckle variance signal was observed as the egg white proteins coagulated. Additionally, by calculating the cross-correlation coefficient in specific areas, denaturized egg white conditions were successfully estimated. These results indicate that SvOCT could be used to monitor the denaturation process of various proteins.

Purpose: Meconium aspiration syndrome (MAS), often progresses to respiratory failure and its’ serious com­ plication, persistent pulmonary hypertension of the newborn (PPHN) is a major cause of neonatal mortality. Early recognition of infants at the risk for respiratory failure in MAS patients is necessary for treatment. So we aimed to identify serum enzymes such as lactate dehydrogenase (LDH), aspartate transaminase (AST), and alanine transaminase (ALT) as serum biologic marker for early detection of respiratory failure in MAS patients. Methods: Infants admitted within 24 hours after birth to Neonatal Intensive Care Unit of Dongguk University Ilsan Hospital and diagnosed with MAS from August 2005 to March 2014 were analyzed retrospectively. Serum enzymes were measured on admission. Results: Of the total 60 patients diagnosed with MAS, 28 were in the positive pressure ventilation (PPV) group and 32 were in the non­PPV group. Six patients progressed to PPHN. Only serum LDH was significantly higher in the PPV group than the non­PPV group (median 1,123 vs. 831, P=0.01). Using the ROC curves, the cut­off value of 964 U/L for LDH offered the best predictive value for PPV requirement (sensitivity 61% and specificity 81%). Serum LDH was significantly higher in MAS with PPHN group than MAS without PPHN group (median 1,791 vs. 904, P=0.013). But serum AST, ALT were not predicting factor for the requirement of respiratory support and development of PPHN among MAS patients. Conclusion: LDH might be a good predicting factor for the requirement of respiratory support and develop­ ment of PPHN among MAS patients.

Lateral resolution and depth discrimination in turbid samples was measured with optical resolution photoacoustic microscopy (ORPAM) and compared to confocal microscopy (CM). ORPAM signal strength and CM resolution were relatively less affected by scattering.

Here we present detailed transmission measurements of ex-vivo lens capsule from 40,000 cm -1 to 800 cm -1 . Time-dependent measurements were also performed to eliminate water absorption.

Thickness estimation is a common task in optical coherence tomography (OCT). This study discusses and quantifies the intensity noise of three commonly used broadband sources, such as a supercontinuum source, a superluminescent diode (SLD), and a swept source. The performance of the three optical sources was evaluated for a thickness estimation task using both the fast Fourier transform (FFT) and maximum-likelihood (ML) estimators. We find that the source intensity noise has less impact on a thickness estimation task compared to the width of the axial point-spread function (PSF) and the trigger jittering noise of a swept source. Findings further show that the FFT estimator yields biased estimates, which can be as large as 10% of the thickness under test in the worst case. The ML estimator is by construction asymptotically unbiased and displays a 10× improvement in precision for both the supercontinuum and SLD sources. The ML estimator also shows the ability to estimate thickness that is at least 10× thinner compared to the FFT estimator. Finally, findings show that a supercontinuum source combined with the ML estimator enables unbiased nanometer-class thickness estimation with nanometer-scale precision.

Multi-spectral imaging (MSI) and its analysis methods were investigated to determine end-point of photothermal damage of tissue. MSI revealed denatured porcine tissue after irradiation of laser with irradiance lower than photothermal damage threshold.

In this study, a photoacoustic detector integrated with Fourier-transform infrared spectroscopy was used to measure biomarkers in gas samples independently. Simulated exhaled breath samples were created by mixing varying concentrations of acetone, ammonia and ethane. The results of these measurements demonstrate the potential of photoacoustic spectroscopy to detect biomarkers from human breath.

We propose a quantification method called Mapped Average Principal component analysis Score (MAPS) to enumerate the contamination coverage on common medical device surfaces. The method was adapted from conventional Principal Component Analysis (PCA) on non-overlapped regions of a full frame hyperspectral image to resolve the percentage of contamination from the substrate. The concept was proven by using a controlled contamination sample with artificial test soil and color simulating organic mixture, and was further validated using a bacterial system including biofilm on stainless steel surface. We also validate the results of MAPS with other statistical spectral analysis including Spectral Angle Mapper (SAM). The proposed method provides an alternative quantification method for hyperspectral imaging data, which can be easily implemented by basic PCA analysis.